meson: rename -Ddebug to -Ddebug-extra

Meson added -Doptimization and -Ddebug options, which obviously causes
a conflict with our -Ddebug options. Let's rename it.

Fixes #76.

meson.build

@@ -737,7 +737,7 @@ conf.set_quoted('GETTEXT_PACKAGE', meson.project_name())
 # substs.set('DEBUGTTY', get_option('debug-tty'))
 #endif // 0
 
-debug = get_option('debug')
+debug = get_option('debug-extra')
 enable_debug_hashmap = false
 enable_debug_mmap_cache = false
 #if 1 /// additional elogind debug mode

meson_options.txt

@@ -53,10 +53,10 @@ option('kexec-path', type : 'string', description : 'path to kexec')
 #        description : 'path to debug shell binary')
 # option('debug-tty', type : 'string', value : '/dev/tty9',
 #        description : 'specify the tty device for debug shell')
-# option('debug', type : 'string',
+# option('debug-extra', type : 'string',
 #        description : 'enable extra debugging (hashmap,mmap-cache)')
 #else
-option('debug', type : 'string',
+option('debug-extra', type : 'string',
        description : 'enable extra debugging (elogind,hashmap,mmap-cache)')
 #endif // 0