Special links recognition when autolinking, nerdz grammar initial support

Following websites will have their own tag:
* `[gist]`: links to gist pages
* `[wiki]`: links to wikipedia articles
* `[twitter]`: links to tweets
* `[video]`: links to videos from `youtube`, `facebook`, `dailymotion` and `vimeo`
* `[music]`: links to tracks from `spotify`, `soundcloud` and `deezer`

Nerdz Grammar:
* Initial Nerdz grammar support
* Added `[user]` tag support (`@user`)
* Added `[project]` tag support (`#project`)