refactor PWA. Faster
fixed tests for pwa
default to CachedPWA
Adds HDF5able serialization support to Menpo
Merge pull request #425 from jabooth/cleanpwa

Faster cached piecewise affine, Cython varient demoted
Merge pull request #427 from jabooth/hdf5able_pull

Adds HDF5able serialization support to Menpo
Merge remote-tracking branch 'upstream/master' into rm_feature_type
Merge remote-tracking branch 'upstream/master' into rm_feature_type