Ported empty folder over to using unGetMsg making emptying folders more memory efficient
Ported empty folder over to using unGetMsg making emptying folders more memory efficient

svn path=/trunk/kdenetwork/kmail/; revision=49319

lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi