CAS-1257: Allow support for custom attribute filters when validating a service

By factoring out the attribute filtering process out of CASImpl, support could be made available via custom injection of filters that would do more other than making sure a registered service received the right set of allowed attributes. This commit places the mapping of filters and services inside the services management tool, and provide a regex attr filter.
CAS-1257: Cleaned up the regex attr filter to no longer be an extension of the default.
CAS-1257: Merge branch 'master' into CAS-1257-1
Merge pull request #204 from Unicon/CAS-1257-1

CAS-1257: Allow support for custom attribute filters when validating a service