Implemented comments by @hamogu
Implemented comments by @aconley
Implemented comments by @cdeil
Implemented comments by @nhmc
Implemented comment by @weaverba137
Implemented comment by @DougBurke
Implemented comment by @ZachAstro
Implemented comments by @crawfordsm
Implemented comment by @keflavich
Implemented comments by Andrew Pontzen
Implemented comments by Andy Casey
Implemented comment by Ole Streicher
Fix line wrap in change addressing Andrew Pontzen's comment
Implemented comments by James Turner
Implemented comments by @taldcroft
Implemented comments by @mservillat
Implemented comments by @timj
Implemented more comments by @cdeil
Added reference to Perry's 2011 review of Python in Astronomy in the introduction
Added a few comments from @mservillat that still need to be addressed