ovsdbmonitor: move to its own data directory

It doesn't have dependencies on any packages that would install into
pkgdatadir, and for Fedora it makes directory ownership work better.
So move ovsdbmonitor python internals to its own data directory.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Ben Pfaff <blp@nicira.com>