Add Prolog filetype support

This patch adds basic Prolog support (only scintilla laxer, there's no
ctags parser). I used swi-prolog for the compiler and run commands which
I believe is the most commonly used prolog implementation. I used the
keywords from here:

https://github.com/mxw/vim-prolog/blob/master/syntax/prolog.vim

data/Makefile.am

@@ -62,6 +62,7 @@ filetypes_dist = \
 	filedefs/filetypes.php \
 	filedefs/filetypes.po \
 	filedefs/filetypes.powershell \
+	filedefs/filetypes.prolog \
 	filedefs/filetypes.r \
 	filedefs/filetypes.restructuredtext \
 	filedefs/filetypes.ruby \

data/filedefs/filetypes.prolog

@@ -0,0 +1,73 @@
+[styling]
+# Edit these in the colorscheme .conf file instead
+default=default
+key_major=keyword_1
+key_minor=keyword_2
+key_directive=keyword_1
+comment_block=comment
+comment_line=comment
+comment_key=comment
+comment_key_error=comment
+identifier=identifier
+variable=default
+anonymous=default
+number=number_1
+operator=operator
+character=character
+character_too_many=error
+character_escape_error=error
+string=string_1
+string_escape=string_1
+string_escape_error=error
+string_eol_open=string_1
+string_verbatim=string_1
+string_verbatim_special=string_1
+string_verbatim_eol=string_1
+
+[keywords]
+# all items must be in one line
+primary=var nonvar integer float number atom string atomic compound unify_with_occurs_check fail false true repeat call once catch throw abolish retract asserta assertz current_predicate clause open close stream_property set_stream_position set_input set_output current_ouput nl put_byte put_char put_code flush_output get_byte get_code get_char peek_byte peek_code peek_char at_end_of_stream write_term write_canonical write writeq read read_term functor arg copy_term atom_codes atom_chars char_code number_chars number_codes atom_length sub_atom op current_op char_conversion current_char_conversion is mod rem div round float float_fractional_part float_integer_part truncate floor ceiling sqrt sin cos atan log findall bagof setof sub_atom ational callable ground cyclic_term subsumes subsumes_chk unifiable use_module compare apply not ignore call_with_depth_limit call_cleanup print_message print_message_lines message_hook on_signal current_signal block exit term_hash redefine_system_predicate retractall assert recorda recordz recorded erase flag compile_predicates index current_atom current_blob current_functor current_flag current_key dwim_predicate nth_clause predicate_property open_null_stream current_stream is_stream stream_position_data seek set_stream see tell append seeing telling seen set_prolog_IO told wait_for_input byte_count character_count line_count line_position read_clause put tab ttyflush get0 get skip get_single_char copy_stream_data print portray read_history prompt setarg nb_setarg nb_linkarg duplicate_term numbervars term_variables atom_number name term_to_atom atom_to_term atom_concat concat_atom atom_prefix normalize_space collation_key char_type string_to_list code_type downcase_atom upcase_atom collation_key locale_sort string_to_atom string_length string_concat sub_string between succ plus rdiv max min random integer rationalize ceil xor tan asin acos pi e cputime eval msb lsb popcount powm arithmetic_function current_arithmetic_function is_list memberchk length sort msort keysort predsort merge merge_set maplist forall writeln writef swritef format format_predicate current_format_predicate tty_get_capability tty_goto tty_put set_tty tty_size shell win_exec win_shell win_folder win_registry_get_value getenv setenv unsetenv setlocale unix date time get_time stamp_date_time date_time_stamp date_time_value format_time parse_time window_title win_window_pos win_has_menu win_insert_menu win_insert_menu_item access_file exists_file file_directory_name file_base_name same_file exists_directory delete_file rename_file size_file time_file absolute_file_name is_absolute_file_name file_name_extension expand_file_name prolog_to_os_filename read_link tmp_file make_directory working_directory chdir garbage_collect garbage_collect_atoms trim_stacks stack_parameter dwim_match wildcard_match sleep qcompile portray_clause acyclic_term clause_property setup_and_call_cleanup message_to_string phrase hash with_output_to fileerrors read_pending_input prompt1 same_term sub_string merge_set
+
+[settings]
+# default extension used when saving files
+extension=pro
+
+# MIME type
+mime_type=text/x-prolog
+
+# the following characters are these which a "word" can contains, see documentation
+#wordchars=_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789
+
+# single comments, like # in this file
+comment_single=%
+# multiline comments
+#comment_open=/*
+#comment_close=*/
+
+# set to false if a comment character/string should start at column 0 of a line, true uses any
+# indentation of the line, e.g. setting to true causes the following on pressing CTRL+d
+	#command_example();
+# setting to false would generate this
+#	command_example();
+# This setting works only for single line comments
+comment_use_indent=true
+
+# context action command (please see Geany's main documentation for details)
+context_action_cmd=
+
+[indentation]
+#width=4
+# 0 is spaces, 1 is tabs, 2 is tab & spaces
+#type=1
+
+[build_settings]
+# %f will be replaced by the complete filename
+# %e will be replaced by the filename without extension
+# (use only one of it at one time)
+compiler=swipl -c "%f"
+
+run_cmd=swipl -q -s "%f"
+
+# Parse syntax check error messages and warnings, examples:
+# ERROR: goo.pro:12:
+error_regex=.+: (.+):([0-9]+).*

data/filetype_extensions.conf

@@ -59,6 +59,7 @@ Pascal=*.pas;*.pp;*.inc;*.dpr;*.dpk;
 Perl=*.pl;*.perl;*.pm;*.agi;*.pod;
 PHP=*.php;*.php3;*.php4;*.php5;*.phtml;
 Po=*.po;*.pot;
+Prolog=*.pro;*.P;*.pl;
 Python=*.py;*.pyw;SConstruct;SConscript;wscript;
 PowerShell=*.ps1;*.psm1;
 reStructuredText=*.rest;*.reST;*.rst;

meson.build

@@ -292,6 +292,7 @@ lexilla = static_library('lexilla',
 	'scintilla/lexilla/lexers/LexTxt2tags.cxx',
 	'scintilla/lexilla/lexers/LexVerilog.cxx',
 	'scintilla/lexilla/lexers/LexVHDL.cxx',
+	'scintilla/lexilla/lexers/LexVisualProlog.cxx',
 	'scintilla/lexilla/lexers/LexYAML.cxx',
 	'scintilla/lexilla/lexlib/Accessor.cxx',
 	'scintilla/lexilla/lexlib/Accessor.h',

scintilla/Makefile.am

@@ -57,6 +57,7 @@ lexilla/lexers/LexTCL.cxx              \
 lexilla/lexers/LexTxt2tags.cxx         \
 lexilla/lexers/LexVHDL.cxx             \
 lexilla/lexers/LexVerilog.cxx          \
+lexilla/lexers/LexVisualProlog.cxx     \
 lexilla/lexers/LexYAML.cxx
 
 LEXLIB_SRCS =                          \