Make all closures into callables

This means we can actually pickle SDMs
Fix a typo in fittingresult

Sneak this fix into this pull request for the appearance
reconstructions.
Remove the constrain_landmarks decorator

This allows us to pickle our objects. However, it is a change
in behaviour that is apparent at lower scales. It has not
been thoroughly tested whether that has a measurable impact
on the performance of fitting.
Change to assert_allclose so I can see the errors
Update test for removal of constrain_landmarks

I ran a benchmark and the results were identical, so this change
only really affects images that are very difficult or have already
diverged.
Change to lowercase function naming for callables
Rename regression_callables to regressors
Merge pull request #10 from menpo/sdm_callables

SDM Callables