GST_PLUGIN_PATH gets split into the user registry some debugging output in registry...

GST_PLUGIN_PATH gets split into the user registry some debugging output in registry rebuilding don't go into =build, ...

Original commit message from CVS:
* GST_PLUGIN_PATH gets split into the user registry
* some debugging output in registry rebuilding
* don't go into =build, =inst, etc
* i really don't know what the current idiom is for the plugin test suites, disabling for now

still pending issues: what to do when other plugin paths are passed on the command
line for existing registries. if the existing registries were built against those
paths, the time checks work, but if not they will need to be rebuilt. i have a feeling
they should be rebuilt in any case, but it's a tricky issue.