Revise patterns for Vim modeline detection

The current expressions fail to match certain permutations of options:

    vim: noexpandtab: ft=javascript:
    vim: titlestring=foo\ ft=notperl ft=javascript:

Version-specific modelines are also unaccounted for:

    vim600: set foldmethod=marker ft=javascript:   # >= Vim 6.0
    vim<600: set ft=javascript:                    # <  Vim 6.0

See http://vimdoc.sourceforge.net/htmldoc/options.html#modeline

test/fixtures/Data/Modelines/iamjs.pl

@@ -0,0 +1,3 @@
+# vim: noexpandtab: ft=javascript
+
+"It's JavaScript, baby";