Implements a preview button in the collection organizer dialog along with an "automatic preview" checkbox

Review Request #100270 - Created Dec. 30, 2010 and submitted - Latest diff uploaded

Maximilian G√ľntner
This patch adds manual preview functionality to the collection organizer dialog. This is very handy when altering the filename scheme and options of large collections ( > 1k files) since the dialog doesn't update the preview widget with every change in the filename configurator. The current functionality can be achieved by clicking on "Automatic Preview". Hope you like it.
-tested auto update by using/clicking each element that connects to the signalmapper
-tested the manual preview button
-moved a collection