If dry-run, render_all prints and exits.
Merge branch 'real_render'
Autoformatted code.
Fixes #10
Added basic command progress printout to render_all.py.
Added unittest for input error in DictionarySpline.
Moved arguments for last test out as arguments.
Removed unused import from morph.py.
Removed unused static member of cvf.
Added ConstraintSpline class an basic unittest for it.
Added testcase for type constraint in ConstraintSpline.
Added arbitrary function test for ConstraintSpline.
DictionarySpline now calls ConstraintSpline to preserve the types of its input.
Added tests for type constraints in tuples.
Added float round-trip test.
Swapped times and values order in tests.
Harmonized Spline interfaces.

Previously, some Splines were constructed with x, y as parameters,
others were constructed with y, x. To harmonize with UnivariateSpline,
all splines have been changed to use the x, y convention. This does
make DummySpline a bit more obtuse though.
Added float test for DictionarySpline.
Hotfix for last commit

Forgot to apply interface changes in Splines to morph.py