Remove trailing whitespace in source files.

Some more additions to bagLib. I'm mainly interested in bags that consists of multiple insertions into the empty bag like for example {|x1;x2;x3|}.
I call these explicitly given, finite bags "simple".

There was a lot of tool support for handling bags that consists of BAG_UNION applications. One can eliminate those for example on both sides of an equation, a BAG_DIFF ...
Now I added support for these "simple" bags. I started adding some things like resorting to bagLib before. However, these addidtion became larger and larger. Therefore, I moved them
into an new file called bagSimpleLib. However, it is imported by bagLib, so the end-user does not need to know this.