Memory Leaks

I've just detected that ags is fully memory leaked.
Affected version:

• 0.3.99
• and some prior versions you don't want to use at all.

This is recognized as very critical but not so trivial to make it realy proper.

fixes:

• Implemented ags_devout_play_free and therefore exists a memory leak.
  • Updated AgsAudio and AgsChannel to use ags_devout_play_free.
• AgsDevoutPlay was therefore refactored.
  • Proper unref of AgsRecallAudioSignal and AgsRecallRecycling related objects while calling done of AgsRecallClass is implemented.
• An AgsTask is required to unref AgsRecallChannelRun and AgsRecallAudioRun related to AgsChannel and AgsAudio. To call it use this task and unref it in a callback.
  • Did therefore ags_line_remove_recall_callback. Further leaks will only be closed for release 0.4.0