Sphinx and NetCDF4 support implemented, new features for pyramid objects

pyramid: all docstrings in numpydoc (package installed) format (used by spinx)
holoimage: removed error, phase was falsely multiplied by pi/2
magcreator: removed create_mag_dist_comb, renamed functions for disc and vortex
magdata: Allows creation of empty MagData objects and easy adding of magnitudes
phasemap: Allows units to be set for plots, added 3D plot
phasemapper: Electrostatic component implemented
projector: Projection now includes thickness profile
docs: support for html, latex and pdf (experimental), use "make *" in shell
scripts: new structure, deleted some compare_* functions, added test_methods
.hpignore: now also ignores *.c and _* files (_build used in docs)