Added JSON API Support to the Media controller

fixes #302 and all references to_label and to_s
removed references to all per_page settings as they are common now

fixes #271 - remove active scaffold plugin

fixes #236 - Installation media are now usable with more than one operating system.

fixes #235 - Small refactoring of the media handling for operating system families: * Use URI class for any URI related operations * Added substitution for $version, $major and $minor in media path * Force use of http(s)|ftp|nfs URI schema: NFS shares have now to be entered in URI form: nfs://server/path/.../ instead of server:/path/.../

fixes #198 - remove activescaffold from Operating systems setting page

fixes #172 - unable to save NFS based medias

before_destroy patch successfully applied, also, added require for ruby-debug

Media tests on green

updated validation column name

updated validations and error message for medias

realigned models to use :though and habtm when it made sense, setup basic AS controllers to support that

added media path validaiton to be either NFS or url

fix the relationship between a host and a media (must be though an OS), added some helpers to auto parse the install path (e.g. NFS or URL) etc

updated migrations to use puppet Rails function of creating the db schema, adjusted what ever it took to get the first Fedora 11 client installed with our kickstart

Added domain model.
removed ensure_not_used from all models and add it to Activerecord:Base class as an initalizer

added os model and fix active record relationship to media and host, hopefully supporting the kickstart integeration for path etc

added media model