use nested for loops in spline formula (C file)
interpolator: use component-wise options
interpolator: save coeffs in per-direction file
interpolator: use cPickle instead of pickle

things are a little faster now...
fix interpolator shared library name
add initialize function to interpolator

clib functionality available without it being called, i.e. no need to
load .gz files if the .so is already there.
Merge branch 'refined_interpolation' into develop