Prefix abstraction incomplete

Some places in the code assume a cm_ prefix even though this is supposed to be configurable.

app/vendors/shells/main() (set up of users view... this will cause the view to not be created since the underlying cm_ tables aren't there)
config/schema/schema.xml (foreign key references)

The former should be easy to fix by looking at the db config as is done elsewhere (eg: extended attributes). The latter probably requires some dynamic munging of the schema file before processing.