Starting feature branch filtersearch
first implementation of the StringFilter
Sceleton for new Search UI
String Filter GUI
Refactor to extend ReqifFilter, and adding supportedOperations.
Label Support for Filter Operations.
Better Comments
Adjust the handling of supported Operators.
throw an exception if StringFilter is constructed with illeagal parameters
unit test for StringFilter

test thrown exceptions
the field SUPPORTED_OPERATIONS should be static
copyright notice
implement NumberFilter
Implementing Filter Functionality
implementing BoolFilter
changed sematics of matching a non existing string attribute
renamed operators for numbers

EQUAL -> IS
NOT_EQUAL -> IS_NOT
Merge branch 'filtersearch' of ssh://git.eclipse.org:29418/rmf/org.eclipse.rmf into filtersearch
implementing DateFilter
DateFilter testing internalAttributes