Changed the popup created for feature info to be a panel and docked it into the east panel.

This will probably need to be cleaned up a bit and is still a work in progress.
Modified VersionedEditor to use the GeogitUtil plugin.
Initial pass at showing feature diffs in the VersionedEditor.
The GeoGit history in the south panel will now  be hidden when the user removes a layer.
Initial pass at displaying ghost geometry for when a feature's geometry changed.
Merge commit '686fb974d084a38a39d0296eb0641673989de47f'
Added a call to geogit's diff when a cell is clicked in the GeoGitHistory panel.
Fixed removal of the diff layer, somehow didn't commit it last time.
Added a check to ensure it is a GeoGit layer being removed before hiding the history panel.
Right clicking on a layer will now give the user an option to show or hide the GeoGit history panel.
Merge commit 'bdd504f3a2b7f924ed8553bdcb5f0cb6c6e69417'
Merge commit '17a831b0e5fab2b04f63f97cb34e41dd788e4b93'

Conflicts:
	webapp/src/gxp/script/plugins/GeoGitHistory.js
Fixed a bug with adding features.

It was trying to build a log call with the feature id of a feature that wasn't fully created yet. Added a null check for the feature id.
Minor fixes to the Attribute and History Panel.

Added quick fix for scroll bars to layer and attribute panels, changed title of attribute panel to the layer name, changed attribute panel to flex with panel.