Add syntax files from upstream vim repository

ftplugin/art.vim

@@ -0,0 +1,19 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim filetype plugin
+" Language:      ART-IM and ART*Enterprise
+" Maintainer:    Dorai Sitaram <ds26@gte.com>
+" URL:		 http://www.ccs.neu.edu/~dorai/vimplugins/vimplugins.html
+" Last Change:   Apr 2, 2003
+
+" Only do this when not done yet for this buffer
+if exists("b:did_ftplugin")
+  finish
+endif
+
+run ftplugin/lisp.vim
+
+setl lw-=if
+setl lw+=def-art-fun,deffacts,defglobal,defrule,defschema,for,schema,while
+
+endif