Merge pull request #729 from pulp/mhrivnak-supportedversion

correcting the supported OS versions in the install docs
Add cancel facility.
Better naming.
refit content sources to use cancel facility.
simpler version.
refit unit tests.
Update style guide for test directory structure
Fix line break
Tighten up the wording
Don't run devel tests on python 2.4
pass an event instead of using Call.
Update for PR comments
Merge pull request #736 from pulp/barnabycourt-update-test-convention-styleguide

Update test convention and line length styleguide
Merge pull request #738 from pulp/barnabycourt-do-not-test-pulp-devel-on-rhel5

Don't run devel tests on python 2.4
refit nodes to use content sources.
remove unused imports.
Merge pull request #734 from pulp/content-sources-cancel

Content sources cancel
correct docstrings.
better naming.
docstring.