Add code to RetrieveFilterController

-RetrieveFilterController.showFilter() made
Work on Double-click to Edit Filters

-Add Controller to FilterListPanel
-More work RetrieveFilterController
-Refactor RetrieveFilterObserver
Merge branch 'dev-iteration2' of https://github.com/gsisko/wpi-suite-tng into dev-iteration2
Finish Double-click to Edit Filters

-Clean up FilterListPanel
-Clean up RetrieveFilterController
Merge branch 'dev-iteration2' of https://github.com/gsisko/wpi-suite-tng into dev-iteration2

Conflicts:
	RequirementManager/src/edu/wpi/cs/wpisuitetng/modules/requirementmanager/filter/NewFilterAction.java
	RequirementManager/src/edu/wpi/cs/wpisuitetng/modules/requirementmanager/list/views/FilterListPanel.java