registrybinary: registry file mode via GST_REGISTRY_MODE
In an embedded system where all services run as seperate users it is useful to have the gstreamer registry readable by all so it can be re-used, in similar manner as a host system where one user have seperate applications running but all share same registry.
To make this possible introducing GST_REGISTRY_MODE for adjusting the changing mode of the registry binary when finishing up with the temporary file (which has restricted access).
Solves #692 (closed)
Edited by Robert Rosengren