to avoid a run time error in gcc 4.7.

--HG--
rename : tools/python/src/decision_funcions.cpp => tools/python/src/decision_functions.cpp

avoids a runtime linking error bug in the MKL that happens when you make
a shared library and try to use it from python.

transform.

since it's easy to mix up the adjust threshold and epsilon arguments
and these checks will usually catch that.  The checks are also very
low cost.