Correct URLs in README.md

Github moved hosted pages to github.io.
First tests with star system popup
Switch to four-space indents

This moves towards PEP-8, which strongly suggests against tabs.
Attempt first working mesh import

The display is b0rk, and events are mishandled to the point of crashing
the app, but presumably something is working, so I'll take what I can
get.
Use pyglet resource to load mesh image

Also don't suppress image load errors; if it fails, it *should* be
fatal!
Display five planets in popup view

This code is still pretty messy, and there's some debugging helper
keypress code that will eventually need to be removed.
Display correct number and positions of planets

Query planet and orbital position model data from star systems and
display appropriately.
Convert function name from "show" to "prepare" to better reflect what
they do.
Adjust planet size based on model size
Adjust planet lighting based on star color
Split/reorganize mesh code

It's for Wavefront objects only, so name it "wavefront".
Split material and mesh code into separate modules.
Need to do this in preparation for using meshes and materials
independently of each other.
Move material loader into material object file

This is purely for organizational/cosmetic purposes.
Refactor mesh code

Move mesh logic into its own module as a wrapper for wavefront objects.
This will allow us to assign multiple textures to a single mesh, which
isn't supported by the wavefront format.
Merge "MaterialGroup" into "Material"

"MaterialGroup" holds only a few data items which can easily be merged
into "Material", and it is confusing to keep them separate.
Refactor wavefront parser

Move from a large if-then-else block to a parser object and functions
via getattr()
Refactor wavefront material parser

Replace if/then statements with parser object and methods
Display appropriate planet texture
Animate planet rotations
Add "cosmetic" orbit inclination and speed
Split wavefront code into new module

New module: https://github.com/greenmoss/PyWavefront
Convert star to 3D mesh

Also make star light coloring more obvious.