Add a Path for Temp directory.
Merge pull request #206 from greboid/pluginpath

Add a path for temp directory.
Switch action to use Paths.
Commit all the files.
Remove filesystem param from actions.
Fix unit test.
Merge pull request #207 from greboid/pluginpath

Switch action to use Paths.
Merge pull request #205 from csmith/master

Add back buffer entries based on events.
Move BackBuffer to ui.messages.

It doesn't really make sense in ui.core now it's doing more...
The classes it's integrating are all in messages.