QmakeProject: SetCurrentNode after renaming

The ProjectExplorer sets the current node after renaming, but since
the qmake project manager is still parsing, that doesn't actually work.
So we do set the current node via a small hack.

Change-Id: Ideefef82740529f7acc71b4d0c467d6818a49710
Reviewed-by: Robert Loehning <robert.loehning@digia.com>
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
QmakeProject: Fix renaming waits 3s for reparse

Task-number: QTCREATORBUG-13176
Change-Id: Id19a08f254dfa844d4adff0baafa29986a515823
Reviewed-by: Robert Loehning <robert.loehning@digia.com>
Reviewed-by: Daniel Teske <daniel.teske@digia.com>