changed: Rename confusing CSimpleDoubleCache class to CDoubleCache
fixed: FileCache-full logic was wrong + implement GetMaxWriteSize() function
fixed: Don't keep reading source when cache is full (fixes #15500)
changed: Use m_StateInput else dvdplayer osd info is 8 seconds delayed
fixed: Calling WaitForData with a large minimum could cause it to block the max. timeout
fixed: Typo in variable name
Merge pull request #5708 from arnova/double_cache_inthread_fix

Double file cache fix. Fixes ticket #15500
vdpau: advanced settings for auto deinterlacing
ActiveAE: slightly reduce buffer size
pthreads: use mutex protocol PTHREAD_PRIO_INHERIT
[linux] Add FDEventMonitor for monitoring file descriptors

Add FDEventMonitor helper thread for monitoring file descriptors for
events (ready for read, ready for write) without the need for spawning
a separate thread with a tight loop around poll()/select().

FDEventMonitor uses an eventfd for signaling poll() instead of a
timeout, therefore it can sleep for long times in case of no events but
still immediately respond to e.g. shutdown.
[AE] ALSA: Add ALSADeviceMonitor for monitoring card removals/additions
[AE] ALSA: Add ALSADeviceMonitor for monitoring ELD changes

ELD changes can happen e.g. when the connected HDMI sink is changed.
[AE] ALSA: Add more logging to device change triggers
[AE] ALSA: Fix DeviceChange event triggered by enumeration

All hctl elements get an SND_CTL_EVENT_MASK_REMOVE event when the ctl
file descriptor is closed, which is done e.g. when re-enumerating
devices.

(SND_CTL_EVENT_MASK_REMOVE & SND_CTL_EVENT_MASK_VALUE) is true, and
therefore we re-triggered enumeration (depending a bit on timing).

Fix that by checking for the special _REMOVE value first and ignoring
those events.
AppMessenger: support for setting volume
AESinkPUSLSE: Use ApplicationMessenger to alter internal volume
VAAPI: Don't return false when unknown driver is used - warn instead
PVR: Add RequestAbort method - so that clients that hang can exit gracefully
DVDDemuxFFmpeg: Fix workaround for filesystems announcing small chunks in demuxer