This is used for giving the data source a hint as to whether or not
it'll be used in a looping situations. It's required for some data
sources which need to know about it's looping state for caching or
whatnot.

The API for the resource management part of this commit may change.

Public issue https://github.com/mackron/miniaudio/issues/355

Signed-off-by: Steven Noonan <steven@uplinklabs.net>