yum cookbook compatibility changes

The latest yum cookbook no longer provides an epel recipe.
yum cookbook compatibility changes

The latest yum cookbook no longer provides a yum_key resource.
yum cookbook compatibility changes

The latest yum cookbook no longer provides a repoforge recipe.
Change base url and rpm url used to retried zenoss from sourceforge.

When you use the /download version of the url you will get a RedirectLimitExceeded error.
Add rpm_file attribute to solve issue #19.

The rpm_file attribute was undefined when setting a custom rpm_url.  This change
will set the rpm_file based on the url passed or allow you to override the rpm_file
by use of an attrinbute.  The attribute's default value is nil.
Revert version update of metadata.rb.

Following contribution rules, a pull request should not update the
metadata version.
Merge branch 'rpm-url-fix' of https://github.com/sfiggins/zenoss-chef-cookbook into sfiggins-rpm-url-fix
updated to support 4.2.5 and make that the default
updates to support new yum cookbooks
Merge branch 'sfiggins-rpm-url-fix'