Removed bignum-classes.

I think I will write these in a separate project instead.
Added Constant and Aegis classes.
Debugged OperationParser and affilies.

Added protected default contructor to GenSolver.
Fixed various generics-errors (missing <T>s, etc.).
Added unittests for OperationParser<Integer>.
Fix a bug discovered by unittests.

GenSolver (OperationParser) modified an args list that had been sent to
the mutable Composition.
This caused the methods of Composition to recurse indefinitely (i.e.
until StackOverflow).