Squashed commit of the following:

commit 22d088ce1a101fc25b32efe182ce163d1e86caa2
Author: Aliaksei Biaskosty <abiaskosty@scnsoft.com>
Date:   Wed Jul 17 11:02:28 2013 +0300

    CMS-1790 Create SchemaTreeGridPanel and friends

- Fixed GridContextMenus in schema and space managers