Initial nightly release

First release. This is still a nightly, as not all bugs are removed.
Version 1.0 will be released as soon as a Schwarzschild black hole has full support

Known bugs:

• Inclinations above 90 degrees don't produce a very sensible image of a black hole when plotting from points
• calculating isoredshifts algorithmically for extreme inclinations (0, 90 or 180 degrees) fails, as isoradials and isoredshifts do not intersect
• black holes with masses larger than 1 may fail to calculate its properties
• code structure should be revised