SciDAVis - Improvements SVN-temp

- fixed a seg fault

- removed several superfluous files
- continued the integration of the new Matrix class; works
faily well now and is much faster than the old one

- copied the missing icons from the trunk
- removed the obsolete matrix dialogs and
some other obsolete code

- added some default shortcuts to Matrix
- fixed some icons

- formula evaluation using the control tabs works now
- in-place formula evaluation when editing cells works now

- preceeded integrating the new Matrix class into
the stable code. Solution:
MatrixView now inherits from MyWidget and
Matrix from MatrixView. Matrix relays
most of its call to a future::Matrix object
while keeping most of its old API.

- fixed a small bug in Matrix

- merged the latest Matrix changes from the trunk
- started integrating the new matrix class
by wrapping the old Matrix interface around
a future::Matrix object

- the cursor now changes to busy while undo or redo are executed
- added highly optimized (very fast, almost no memory usage)
transpose and mirror operations to Matrix

- added a method to initialize global defaults at startup
- added/implemented several methods in Matrix including
image import and copy/duplicate