add some verification against MATLAB output

Add a new test which checks that the output from the Python code matches
that of MATLAB to within machine precision.

We also need a nasty workaround for Python 2/3 incompatibility with npz.
The npz format uses pickle to store objects. The pickle format is
incompatible between PYthon 2 and 3 due to Unicode encoding issues. We
work around this by ensuring that we only store plain ol'arrays in the
npz file. It's mucky, but compatible.
add emacs/gedit backup file to .gitignore
Rotational symmetry mod, dtwavexfm2b and dtwaveifm2b
Added utils.py, containing drawedge and drawcirc for generating synthetic images
docs: add stub for variant transforms

Add a place where variant transforms may be documented.
docs: add dtcwt.utils to API reference

Update docs/reference.rst to add documentation for the dtcwt.utils
module.
re-indent replacing tabs with spaces
Update variant.rst
Some doc updates (modified wavelet images)
Added testing capability, fixed documentation table issue
Verification suite changes. verificationb.mat is static.
remove *~ editor files