Rewrote wxSound:

Rewrote wxSound:
* Get rid of #if wxUSE_SOUND from header.  wx/sound.h checks this already.
* Get rid of pragma interface/implementation. Apple GCC dislikes them anyway.
* Allow source file to use precompiled headers (wx/wxprec.h)
* Include only needed AppKit/Foundation headers, not AppKit/AppKit.h.
* Implement simple constructors inline in header.
* Get rid of m_sndname and m_waveLength instance variables.  They aren't used.
* Add copy constructor (why not).
* Move implementation of byte-array constructor into LoadWAV for consistency
  with UNIX wxSound.
* LoadWAV (what was in the constructor) now properly allocs, inits, and
  releases NSData.  The old code for this was not valid.
* Rename lastSound to s_currentSound.
* Rename isLastSoundLooping to s_loopCurrentSound.
* Ignore the sound:didFinishPlaying: delegate message if it is received
  for an NSSound other than s_currentSound.
* Create should not Stop the current sound.
* Don't use NSBundle to get a resource sound but use [NSSound soundNamed:]
  which will include system sounds.
* Playing a sound synchronously uses wxEventLoop::Dispatch which will
  really block (not spin the CPU like Yield).  The sound is considered
  finished playing when s_currentSound is set to something else.  In order
  to make sure we don't get stuck in this event loop the delegate
  calls wxApp::WakeUpIdle if it releases s_currentSound.
* Have IsPlaying() check to make sure s_currentSound is not nil since
  only messages returning another object or void are allowed to be
  sent to nil objects.

Changes involving retain/release
* Get rid of comment about tricky API, it's not.
* Get rid of isLastSoundInScope. Cocoa has proper reference counting.
* Add SetNSSound which, like the rest of wxCocoa, retains/releases
  appropriately, sets the delegate, and logs when WXTRACE=COCOA_RetainRelease.
* Destructor does SetNSSound(nil) which will always release the NSSound.
  Create and LoadWAV use SetNSSound method like the rest of wxCocoa.
* Make the delegate always release s_currentSound if not (or if done) looping.
  DoPlay sets s_currentSound to m_cocoaNSSound after retaining it so that
  the delegate can always safely release it.
* Stop, like everything else, does not need check of isLastSoundInScope

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@30043 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775