updates
- added load/save MS as XML feature
- fixed weight adjusting issues for appending branch from library into node
- synchronized building distribution zones dropdown with clicks in TreeView
- added checks in shapefile loading to generate appropriate error message
- added confirmation before building exposure after changing option
- adjusted main windows disabling sequence when loading project
- fixed bug in ZoneFootprintToGrid operator

- updated test cases

generic
- added checks to make sure DB for use are all available