Added the styler tool
Using describeLayer request to check to see if a layer is a layer or a layer group
Disable the "show/hide history" item in the context menu if it isn't a geogit layer
Disabled the distance/bearing tool
Added basic merge functionality to Salamati.
Merge branch 'mergeUI'

Conflicts:
	webapp/src/app/app.js
	webapp/src/gxp/script/plugins/DiffPanel.js
Added geometry to merge review.

Moved the diff geometry things from DiffPanel to GeoGitFeatureAttributeGrid since the two are tied together.
Added a function to GeoGitUtil to get the name of the attribute for geometry since it was duplicated in many places.
Merge commit '2032a63bcb100dc69f2c14439ded87e9ade3d373'

Conflicts:
	webapp/src/app/app.js
	webapp/src/gxp/script/GeoGitUtil.js