Fixed code style in EngineDelay
Removed echo from EngineDelay. Solution copied from pfl_delay.patch from Ywwg Bug #225966
Added EngineDelay for Master and Headphone output
bypass delay puffer if
Bypass delay buffer if delay is 0
add apreference option for delay
Tweak prototypes: Use const; CSAMPLE and avoid ambigous long
Introduce SampleUtil::clear() and use it
splitt m_pSoundManager->requestBuffer()
setup infrastructure for read write mode
Feed the non clock reference devices from the reference device callback.
Use a two page buffer to have only on PA call for writing.
read m_pStream only one time per function and made it volatile to avoid possible race conditions
Fix crystal drift and error in memcpy size calculation
Merge remote-tracking branch 'upstream/master' into two_soundcards

Conflicts:
	src/sounddeviceportaudio.cpp
	src/soundmanager.cpp
	src/soundmanager.h
get rid of m_pDownmixBuffer buffer
Merge remote-tracking branch 'upstream/master' into two_soundcards
Finished read buffer part.

This does not work well if the clock reference card is a USB 2.0 soundcard.
So we need to switch back to a two callback solution
Merge remote-tracking branch 'rryan/multi_soundcard_fixes' into two_soundcards

Conflicts:
	src/sounddevice.cpp
	src/sounddevice.h
	src/soundmanager.cpp
Merge remote-tracking branch 'daschuer/multi_soundcard_fixes' into multi_soundcard_fixes