SciDAVis - Improvements SVN-temp

- removed AbstractAspect from the base classes of
AbstractSimpleFilter since I think an undo aware
class that manages the filter is better than implementing
undo commands for all filters
- improved AbstractSimpleFilter
- improved SimpleCopyThroughFilter
- wrote a SimpleMappingFilter and added a test case
for it to the column unit test

- did some renaming for consitancy and to avoid naming conflicts
- polished/improved AbstractFilter and AbstractSimpleFilter

- implemented conversion between SciDAVis enum values
and strings using the meta object system
- implemented save/load to/from XML for columns

- improved the way comments are displayed in table headers

- added/revised some more icons for table actions

- added some new icons for table actions

- added files I forgot in previous commit

- added icons for the 3 column types
- implemented column sorting
- implemented several more Table methods
- added support for dragging columns to another position in tables
- added support for undo stack macros to AbstractAspect
- added preliminary method to manage systemwide keyboard
shortcuts in Project

- added icons for mask/unmask
- added a form designed with Qt-Designer that will replace the column
options dialog (I call this options tabs for now)
- implemented most of the UI of TableView (context menus, options tabs)
- implemented several methods in Table
- a selection model for Table/TableView is now stored in TableModel

- continued working on Table and related classes