Initial work on integrating ZeDB
CTags module now uses symboldb as a backend rather than the `tags` file.
Reduce number of indices
Tweaked auto complete and goto UI with icons.
Completions can now also set a "type" which is used as an icon, options:

* file
* action
* function
* type
* local
* snippet

Icons also appear in the goto symbol UI.

Also: PHP and JavaScript indexers now index function arguments
Globally renamed ctags to symbol. CTags are out.
Added syntax highlighting for Matlab.
Merge branch 'master' of github.com:zedapp/zed