Avoid raising the main window after loading project

This is especially annoying when starting Qt Creator with a session or
project from the command line.
ModeManager::setFocusToCurrentMode() should really only set the focus.
Callers that also want to raise the main window (none at the moment)
should do that explicitly.

Change-Id: Ib9c3026184bd25a6e2cd4bb557bd9981ce91d569
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Niels Weber <niels.weber@digia.com>