Split out the registration of the metadata API and its implementation. Make a
GType for each metadata API. This allows us to store extra information with the
API type such as the tags.
Change the buffer API so that we can get the metadata using the API GType.
Change the query API so that we use the metadata API GType in the allocation
query instead of a string.
Update netaddress and unit tests
Original commit message from CVS:
Patch by: Ole André Vadla Ravnås <ole.andre.ravnas@tandberg.com>
* win32/common/libgstbase.def:
* win32/common/libgstcontroller.def:
* win32/common/libgstdataprotocol.def:
* win32/common/libgstnet.def:
* win32/common/libgstreamer.def:
Add more missing symbols, remove some duplicates, and sort
as the 'sort' command sorts it (partially fixes#493983).