[AstroPy] astrolib pages migrated to new scipy wiki

[Perry Greenfield]

I believe I have migrated all the astrolib pages from the old wiki to 
the new one. In all the reformatting, I certainly must have made some 
mistakes (or otherwise formatted things contrary to authors' wishes or 
intent). So if you are the primary author of one of these pages, please 
take a look at them and edit them if necessary. Comments have been 
included in the body in a somewhat inelegant way. If someone would like 
to improve that, please do. Let me know if I've missed any pages.



I haven't migrated the astropy page yet (I'm going to see if Russell 
wishes to do that himself)

Perry