Tidy

I've tried not to be too obtrusive, but have renamed members with
comment lines that would be redundant had the names been subtlety
different.
Refactor of NewtAble

Now works with IVM, or at least should do, I had trouble compiling
because of other code. We can merge branches now and all work on the
same branch!
Old NewtAble

In case it's ever needed. In the old format and now missing stuff from
the new version as well. Shouldn't be compiled or included in anything.
Merge branch 'newtAble' of https://github.com/avincer/solver into newtAble

Conflicts:
	ivm.h
Update rest of code following changes to IVM.