COMP: Remove redundant test and unify tolerances

TestParametricFunctions.py existed in two modules. The version in
Filters/Sources used random numbers to populate the splines. This was
undesirable for producing consistent results across platforms.

The version in Common/ComputationalGeometry uses explicit points and
matches the points in the corresponding .tcl test.

Also, the .tcl and .py tests had different image tolerances. This
patch unifies those tolerances.

There are currently four baselines for these tests. Once merged, we
will remove all of the alternate baselines.

Change-Id: Ie09a6a27e0856596fcda2df7cec2d11ee279ed78
Merge topic 'TestParametricFunctions' into master

ca880016 COMP: Remove redundant test and unify tolerances