Add syntax files from upstream vim repository

ftplugin/cs.vim

@@ -0,0 +1,33 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim filetype plugin file
+" Language:	C#
+" Maintainer:	Johannes Zellner <johannes@zellner.org>
+" Last Change:	Tue, 09 Mar 2004 14:09:33 CET
+
+" Only do this when not done yet for this buffer
+if exists("b:did_ftplugin")
+  finish
+endif
+
+" Don't load another plugin for this buffer
+let b:did_ftplugin = 1
+let s:keepcpo= &cpo
+set cpo&vim
+
+" Set 'formatoptions' to break comment lines but not other lines,
+" and insert the comment leader when hitting <CR> or using "o".
+setlocal fo-=t fo+=croql
+
+" Set 'comments' to format dashed lists in comments.
+setlocal comments=sO:*\ -,mO:*\ \ ,exO:*/,s1:/*,mb:*,ex:*/,:///,://
+
+if has("gui_win32") && !exists("b:browsefilter")
+    let b:browsefilter = "C# Source Files (*.cs)\t*.cs\n" .
+		       \ "All Files (*.*)\t*.*\n"
+endif
+
+let &cpo = s:keepcpo
+unlet s:keepcpo
+
+endif