The functions in arithmetic.hpp would check the concepts Point and ConstPoint
on Point2, instead of checking Point on Point1 and ConstPoint on Point2.
This would cause concept check failures when attempting to operate from
a ConstPoint.
Adaptions to test with respect to new namespace model
Removed GMP/CLN and, where it was present, replaced by TTMATH
Small fix in comparable_distance test
All testfiles use bg as alias now
[SVN r66811]
