Includes following master commits:

commit 6536d0eb
Author: Lionel Elie Mamane <lionel@mamane.lu>
Date:   Tue Apr 23 06:44:57 2013 +0200

    reword comment

commit 5143e162
Author: Lionel Elie Mamane <lionel@mamane.lu>
Date:   Tue Apr 23 06:44:42 2013 +0200

    isEmpty() instead of getLength()==0

commit f0c38b63
Author: Olivier Ploton <olivier.ploton@univ-tours.fr>
Date:   Wed Dec 12 22:04:38 2012 +0100

    Base: fix incorrect field removal in criterion inside query design view

Change-Id: I2fedae672c24a269fca3dfc1bacc66fd53fc61af
Signed-off-by: Miklos Vajna <vmiklos@suse.cz>