Vim: update JS snippets

Add docblock snippet, and mark a couple others as only active at the
beginning of a line.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Vim: add some PHP snippets

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Vim: override CamelCasing on UltiSnips directory

This has always bugged me, seeing as all the other directories use
lowercase (and even the upstream repo is "ultisnips.git" in lowercase).

The ideal name here would be "snippets", but UltiSnips apparently
reserves that for snipMate snippets.

Signed-off-by: Wincent Colaiuta <win@wincent.com>