Fix for issue #30

Updated approach to calculateAngle() in Angle2d.java and Angle3d.java
matched axis angle convention (deg)
fixed parsing of obj files with empty lines
fixed variable length whitespace for faces

Support for variable length whitespace might have to be added to v and
vn as well, but so far I've not seen any files that were not single
spaced.
Merge pull request #39 from ennerf/master

fixed some incompatibilities with Meshlab obj file format