Clarify the limitations of get_provider(packagename) (merge from 0.7 trunk)
Clarify the limitations of get_provider(packagename)
(merge from 0.7 trunk)

--HG--
branch : setuptools-0.6
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/branches/setuptools-0.6%4046714

pypa/setuptools,pypa/setuptools,pypa/setuptools