Add snippets for requirejs module definitions for coffee- and javascript

The snippet that generates a require block is called `reqjs` in order to
have no collision with the existing `req` snippet.
Added print_r snippet in php
Merge pull request #420 from ethervoid/printr_snippet

Added print_r snippet in php
Avoid collision with print_r snippet
More adecuate naming
Add tex listings snippets.
Merge pull request #422 from cirosantilli/tex-listings

Add tex listings snippets.
Modify js proto and add node snippets
Merge pull request #423 from ConnorAtherton/cla-node-snippets

Modify js prototype and add node snippets
Changed @todo to TODO
Merge pull request #424 from X4fyr/master

Changed @todo to TODO
adding Ada snippets
Merge pull request #425 from obaoba/master

add Ada snippets
add pandoc snippet for UltiSnips
Fixed link to vim-addon-manager in readme
Merge pull request #427 from ondrowan/patch-1

Fixed link to vim-addon-manager in readme
Update snippets.
pull request review
Remove useless placeholder
Add tex hyperlink snippets.