CC-4957 : Replay Gain undefined error, json response not being sent back properly.
Merge branch '2.3.x' of dev.sourcefabric.org:airtime into 2.3.x
Revert "CC-4955: Datatables saves its parameters twice on every page load"

This reverts commit 39ec07e71c11a04290df988731549b589bddea7b.