Add backwards compat support for Oz disksize feature
remove second set of of Rackspace post scripts
force urls from jeos config to be strings

In RHEL 6 the url grab fails without this because, presumably, it is being passed a unicode
string.  Adding the str() wrapper resolves this and should be harmless.
Merge pull request #297 from aeolusproject/bug/unicode_urls

force urls from jeos config to be strings
Merge pull request #298 from aeolusproject/bug/plugin_spec

remove second set of of Rackspace post scripts
Merge pull request #299 from aeolusproject/feature/oz_disksize

Add backwards compat support for Oz disksize feature