TEIIDDES-1674 initial commit of DdlImporter extension property handling
teiiddes-1740: Added check to see if the source requires a password before prompting for password.
TEIIDDES-1755: Avoid synchronizing vdbs about to be deleted

* DeleteResourcesRefactoring
 * Only index and sycnhronize a related vdb if the vdb itself is not
   among the resources being deleted.

* AbstractResourcesRefactoring
 * Provide the collection of resource and children as standard for all
   refactoring classes
Model Explorer Move Action should handle multiple file selection

* ModelExplorerMoveAction
 * Allow multiple selections

* MoveRefactorAction
 * Although multi-selections are allowed, it is incredibly complex to
   handle all the logic associated with moving resources from different
   directories into the same destintion. Thus, limit the move to only
   moving resources from the same directory.

* MoveRefactoringResources
* RefactorResourcesUtils
 * Multi-selections reveal limitations in the current move refactoring logic
  ** Use a history cache to stop the repeated processing of a resource
     that is related to more than 1 selected resource.
  ** The calculation of import changes needs to know the collection of
     resources being moved since they should be ignored when updating
     any import locations.
Merge pull request #182 from mdrillin/TEIIDDES-1674

TEIIDDES-1674 initial commit of DdlImporter extension property handling
Merge pull request #183 from tejones/teiiddes-1740

teiiddes-1740:
Merge pull request #184 from phantomjinx/TEIIDDES-1755

Teiiddes 1755 and Move Refactoring Fixes