[AE/CA] - implement streamsilence flag (releases powermanagement assertion which is hold since lion even when holding a shared audio device open)
Add key mapping for the power button
Add support for sleep key in Linux
Move the Nyxboard sleep key mapping to the main keymap
Use key name not id in the Nyxboard mapping for F4
[rbp] Fix for audio out of sync part 2
[rbp] Apply volume control at audio_mixer when possible
[OSX] Remove unused function Cocoa_GetAppVersion()

When cleaning out the CFStringGetCString references I noticed that
this function isn't used anywhere. So instead of changing it, I rather
just remove it.
Merge pull request #2083 from tru/remove_cocoa_get_app

[OSX] Remove unused function Cocoa_GetAppVersion()
Merge pull request #2081 from popcornmix/mixer_volume

[rbp] Apply volume control at audio_mixer when possible
Merge pull request #2080 from popcornmix/timestamp_fix2

[rbp] Fix for audio out of sync part 2
[OSX] Remove all direct calls to CFStringGetCString and CFStringGetCStringPtr

This adds a new util function DarwinCFStringToString that handles errors
and tries to first get the pointer otherwise copies the string into a
std::string. It also makes sure to use CFStringGetSystemEncoding()
everywhere so we don't get in trouble for using a hardcoded encoding.
Merge pull request #2082 from tru/cfstring_get_cstring_spring_cleaning

[OSX] Remove all direct calls to CFStringGetCString and CFStringGetCStringPtr
[osx] - fix sleep button for nyxboard - use the sleep button key code which will be introduced via PR #2077
Merge pull request #2077 from jhsrennie/sleepkey

Add support for the power and sleep buttons
Merge pull request #2075 from Memphiz/streamsilence

[AE/CA] - implement the advancedsetting for streamsilence