QmlProfiler: Restore binding loop markers in overview.

Change-Id: Id0bf7cb9b63c424247f669f21b5782ab99ea873e
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
C++: Rename ModelItemInfo to IndexInfo.

And move it into its own header and source files.

Change-Id: I37401badd819e028e1d767425759dc0ff27afe31
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>