Change sublime text path select priority on mac.

User changed symbolic link for sublime binary is now top priority,
since this allows users to actually specify which version of sublime
they want to use. Sublime text 2 binary has higher priority over
sublime text (3) binary, since sublime text 2 is considered more
stable.
Cache for fasd --init

Using cache technique for faster fasd --init as shown at:
 https://github.com/clvv/fasdi#install
Merge pull request #1779 from lorn/fasd_update

Cache for fasd --init
Merge pull request #1774 from kevinxucs/sublime-default-2

Change sublime text path select priority on mac.