Fix that names of custom locator filters are ignored.

We need to set the display name on the interface, and give the filters a
unique id (simply numbered).

Task-number: QTCREATORBUG-11051
Change-Id: I8fdbf52fb538f071a9257ac57d2151f58f8d2157
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
TextEditors: Fix wrong revision marker after undo/redo

The block revisions where no longer reset when the editor goes back to
unmodified state (when doing undo or redo), which broke in the recent
refactoring.

Task-number: QTCREATORBUG-11402
Change-Id: I2de24fcc42568f3f7e48a94d391bb9b83c8c4280
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>