Reorganize files

* Move non-ST-commands under lib
* Use simple modules if possible
* Change import paths as needed

--HG--
rename : sublimetext/FSharp/fsac/server.py => sublimetext/FSharp/lib/fsac/server.py
First implementation of symbol help text
Use helper functions
Merge pull request #398 from guillermooo/st-refactor

ST refactor