added open_api_page function
Added option to get URL without opening in browser (and cleaned up docstring)
Fixed find_api_page so that modules will also be located correctly
Clarified docstring
Added test for find_api_page
Merge pull request #663 from eteq/docs-lookup (with manual merge)

Note that this *replaces* 43607c237800e53799bd2de4936e743e3475d3e9 -
that was an incorrect merge from an out-of-date version of this branch.

Conflicts:
	astropy/utils/misc.py