Add "busydialogdelayms" advanced setting.

Provides control over the delay until busy dialog is shown when starting
video playback.
PVR: Resolve channel dummy in GUIWindowPVRTimerSettings

When using Backend channel number , use channel unique ID member instead channel number
PVR: Cosmetics in GUIWindowPVRTimerSettings
remove old unused renderer files
Defer demuxer pause until buffers full
changed: Make network buffer more flexible/configurable
changed: Move read cache logic from DVDPlayer to CFile
fixed: Tab -> space
[Players] Avoid jumping volume to maximum after trickplay
For players that control volume, if the speed changes (e.g. with ff/rew) the volume gets reset to maximum.
This change sets it back to current value, although I question why it is being changed at all.
Do any players require muting during trickplay?
[win32] PeripheralBusUSB::PerformDeviceScan: rename parameter for clarity
[win32] PeripheralBusUSB: declare constant values as "const"
Values not supposed to be changed is better to declare as "const" to allow compiler optimize better.
[win32] PeripheralBusUSB::PerformDeviceScan: check for real memory allocation
[win32] PeripheralBusUSB::PerformDeviceScan: add check for presence of PID and VID
[win32] PeripheralBusUSB::PerformDeviceScan: Cosmetics
[win32] PeripheralBusUSB::PerformDeviceScan: optimization
[win32] PeripheralBusUSB::PerformDeviceScan: skip device on error and get rest of the devices; plus small optimization
[win32] PeripheralBusUSB::PerformDeviceScan: Allow reuse of buffer
instead of multiple frees/mallocs
[win32] PeripheralBusUSB::PerformDeviceScan: add fast detection of HID devices
[win32] PeripheralBusUSB::PerformDeviceScan: use function designed for device ID extraction
ActiveAE: make viz not observe volume and mute