TextEditors: Remove "optimization"

I couldn't find a situation where this code actually resulted in
performance improvement.

Change-Id: I7d905af36ef11dcba43030dc83670c3d1558f650
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
TextEditors: Move some auto-indentation code to document

From the editor widget. Also name them autoIndent/autoReindent to
distinguish from the manual indent functions.

Change-Id: I4e1b9d503f53870b669fee66467e5e567eacefec
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
TextEditors: Move manual (un)indent code to document

Change-Id: I01e93a15b8280a55c31db6be28fe6eb39c7babb0
Reviewed-by: Eike Ziller <eike.ziller@digia.com>