Test all features

Add cases for attribute highlight on and off, block syntax by lang
and emmet-vim group names, OnChangeVueSyntax(), matchit, .wpy,
initial_indent as syntax and tag.syntax, and syntax after reloading.

Also check indenting a file after removing all indent with
g:test_flatten, which fails before the end tag fix as closing tags at
column 0 were taken as block end tags.

test/run.sh

@@ -17,7 +17,7 @@ done
 if [ $# -gt 0 ]; then
   cases=$*
 else
-  cases=$(ls test/cases/*.vue | sed 's#.*/##; s#\.vue$##')
+  cases=$(ls test/cases/*.vue test/cases/*.wpy 2>/dev/null | sed 's#.*/##; s#\.[a-z]*$##')
 fi
 
 out=$(mktemp)