Add new check-packages script

Add a new Python script to replace check-unbuilt-packages and
ood-packages.  The script will identify version skew between
the Git repository and the APT repository.
Remove obsolete scripts

Delete check-unbuilt-packages and ood-packages which are now
obsolete (replaced by check-packages.py)
Add raspbian-wheezy

Add an entry for raspbian-wheezy, which somebody added to the locker
without adding it here.