CAY-1962 | Implement CayenneTable column resize on double-click on the header separator
Squashed commit of the following:

commit 5456145bf1f19d2c7247aa9da4838c0ccac7b246
Author: Savva Kolbechev <s.kolbachev@gmail.com>
Date:   Thu Oct 23 13:47:39 2014 +0300

    CAY-1837 | minor fix

commit a81709007e5d727cf88f0ab8892691636394243f
Author: Savva Kolbechev <s.kolbachev@gmail.com>
Date:   Thu Oct 23 13:19:45 2014 +0300

    CAY-1837 | Generate classes/generate DB schema should be enabled when higher tree objects are selected