Add the ability to disable inline math (#378)

Fixes #196

Author: tnyeanderson

doc/pandoc-syntax.txt

@@ -38,6 +38,7 @@ CONFIGURATION				       *vim-pandoc-syntax-configuration*
   - ellipses
   - quotes
   - inlinecode
+  - inlinemath
 
   To review what are the rules for, look for the call to |s:WithConceal| in
   syntax/pandoc.vim that takes the corresponding  rulename as first argument.

syntax/pandoc.vim

@@ -263,8 +263,13 @@ call s:WithConceal('html_c_e', 'syn match pandocHTMLCommentEnd /-->/ contained',
 " Unset current_syntax so the 2nd include will work
 unlet b:current_syntax
 syn include @LATEX syntax/tex.vim
-syn region pandocLaTeXInlineMath start=/\v\\@<!\$\S@=/ end=/\v\\@<!\$\d@!/ keepend contains=@LATEX
-syn region pandocLaTeXInlineMath start=/\\\@<!\\(/ end=/\\\@<!\\)/ keepend contains=@LATEX
+if index(g:pandoc#syntax#conceal#blacklist, 'inlinemath') == -1
+    " Can't use WithConceal here because it will mess up all other conceals
+    " when dollar signs are used normally. It must be skipped entirely if
+    " inlinemath is blacklisted
+    syn region pandocLaTeXInlineMath start=/\v\\@<!\$\S@=/ end=/\v\\@<!\$\d@!/ keepend contains=@LATEX
+    syn region pandocLaTeXInlineMath start=/\\\@<!\\(/ end=/\\\@<!\\)/ keepend contains=@LATEX
+endif
 syn match pandocEscapedDollar /\\\$/ conceal cchar=$
 syn match pandocProtectedFromInlineLaTeX /\\\@<!\${.*}\(\(\s\|[[:punct:]]\)\([^$]*\|.*\(\\\$.*\)\{2}\)\n\n\|$\)\@=/ display
 " contains=@LATEX