Adding files from PR 346
Updated data init file according to PR 346
Added circle and C images for 2D registration examples (PR 346)
Updated fetcher according to PR 346
Added regtools from PR 346
Updated examples and setup according to PR 346
RF: adding discretization information for DiffeomorphicMap and renaming discretization information for domain and codomain. Now it is much simpler to handle default input/output discretization of the map, and the naming is much more clear.
BF: passing right prealigning matrices to DiffeomorphicMap
TEST: added tests for diffeomorphic map simplification and affine warping in 2D and 3D. Removed deprecated cython code.
TEST: added tests for vector_fields module. Removed deprecated functions.
DOC: added missing documentation
TEST: added missing tests for expectmax module
TEST: added tests for sumsqdiff module
TEST: added missing tests for crosscorr module
TEST: added tests for sumsqdiff module
RF: removed the default value '-1' from warping functions, using None instead and string 'identity' to disambiguate
RF: renamed functions with substrings 'image' and 'volume' to '2d' and '3d' for consistency
RF: renamed 'disc_shape' and 'disc_affine' ('discretization shape, affine') to 'disp_shape' and 'disp_affine' ('displacement_shape, affine')
RF: renamed the the partial diffeomorphisms from 'forward_model' and 'backward_model' to 'static_to_ref' and 'moving_to_ref'
TEST: reducing comparison precision in statistics (we compute them using 32-bit variables)