Updated so it saves properly

SaveSalstatNative.py is a hacky-little module that saves in a short XML
format. As well as pickled data vectors, it has information about
variables.
Chart window, XML import

The chart window now functions after a fashion. Lots to do yet – it's
not even linked to the main code. The native file function should now
load. Needs lots of testing.
Latest commits

Now has basic charts, icons, a toolbar with text for the main window
and other minor changes.
Slight code clean-up

Just removing lots of cruft from the code