Adds Transience package for Sublime Text 2 and 3

Transience is a small plugin for both Sublime Text 2 and 3 that tries to automatically create transient views in empty groups, and optionally overrides the new file short cut to create transient views instead of normal tabbed views.

I couldn't find any built-in functionality or existing plugins for this in Windows so this plugin attempts to fix the problem.
Removes Transience from the name map
Merge pull request #1581 from jakelucas/master

Adds Transience package for Sublime Text 2 and 3