Fixed bug with retain cycle in RATreeNodeInfo.
Added new method to RATreeView's delegate - treeView:estimatedHeightForCellForItem:treeNodeInfo.
Added new properties to RATreeView - estimatedRowHeight and separatorInset.
Fixed bug in implementation of the treeView:willSelectRowForItem:treeNodeInfo method.
Updated documentation and podspec file.
Fixed bug in implmentation of the tableView:estimatedHeightForRowAtIndexIndexPath method.