Adding a unit test which will test that all distribution urls changed between origin/master and the current version are valid remotes with branch names.
Fixups from review.
 - Adding a unit test which will test that all distribution urls changed between origin/master and the current version are valid remotes with branch names.
 - Sending Warnings to stderr
 - rewrapping
 - validate against distribution files in the index only.
 - name typo
Merge pull request #5501 from ros/url_checking

Url checking