changed ticks etc doc so that axis labels are displayed
currently set_major_formatter does not support Formatter objects, fixed doc
Merge pull request #77 from anizami/docs

changed ticks etc doc so that axis labels are displayed
matplotlib methods now link to matplotlib's docs
Merge pull request #80 from anizami/broken-doc-links

Matplotlib methods now link to matplotlib's docs
Updated description
Minor fixes to docs
Added m.mm and s.ss to the tick label format docs
Auto-set coord_meta for string frame types
Put API on separate page
Added section on overlaying coordinate systems
Fix compatibility with Astropy 0.3
Updated supported frames
Added example for contour overlay and ax.scatter
Added custom frames to index
Import CoordinatesMap into __init__ to include it in the API docs