0.5 -> 0.6

Signed-off-by: Matt Bentley <mbentley@mbentley.net>

syntax/dockerfile.vim

@@ -1,6 +1,8 @@
 " dockerfile.vim - Syntax highlighting for Dockerfiles
 " Maintainer:   Honza Pokorny <https://honza.ca>
-" Version:      0.5
+" Version:      0.6
+" Last Change:  2019 Aug 16
+" License:      BSD
 
 
 if exists("b:current_syntax")
@@ -12,20 +14,13 @@ let b:current_syntax = "dockerfile"
 syntax case ignore
 
 syntax match dockerfileKeyword /\v^\s*(ONBUILD\s+)?(ADD|ARG|CMD|COPY|ENTRYPOINT|ENV|EXPOSE|FROM|HEALTHCHECK|LABEL|MAINTAINER|RUN|SHELL|STOPSIGNAL|USER|VOLUME|WORKDIR)\s/
-highlight link dockerfileKeyword Keyword
+
+syntax match dockerfileKeyword /\v(AS)/
 
 syntax region dockerfileString start=/\v"/ skip=/\v\\./ end=/\v"/
-highlight link dockerfileString String
 
 syntax match dockerfileComment "\v^\s*#.*$"
-highlight link dockerfileComment Comment
-
-set commentstring=#\ %s
 
-" match "RUN", "CMD", and "ENTRYPOINT" lines, and parse them as shell
-let s:current_syntax = b:current_syntax
-unlet b:current_syntax
-syntax include @SH syntax/sh.vim
-let b:current_syntax = s:current_syntax
-syntax region shLine matchgroup=dockerfileKeyword start=/\v^\s*(RUN|CMD|ENTRYPOINT)\s/ end=/\v$/ contains=@SH
-" since @SH will handle "\" as part of the same line automatically, this "just works" for line continuation too, but with the caveat that it will highlight "RUN echo '" followed by a newline as if it were a block because the "'" is shell line continuation...  not sure how to fix that just yet (TODO)
+hi def link dockerfileString String
+hi def link dockerfileKeyword Keyword
+hi def link dockerfileComment Comment