COMMON: Add fallback macros for INT64_C and UINT64_C
SOUND: Add RewindableAudioStream::getLength()

Estimate the total number of samples per channel in this stream.
SOUND: Add RewindableAudioStream::getDuration()

Estimate the total duration of the stream by using
getLength() and getRate().
SOUND: Implement getLength() for MP3 AudioStreams
SOUND: Implement getLength() for Vorbis AudioStreams
SOUND: Implement getLength() for PCM AudioStreams
SOUND: Implement getLength() for ADPCM AudioStreams
SOUND: Implement getLength() for ASF AudioStreams
MAIN: Use the AudioStream length estimates in exportWAV
BUILD: Add dependency on Boost.Thread
BUILD: Add dependency on Boost.Atomic
BUILD: Add dependency on Boost.Chrono
COMMON: Implement Mutex based on boost::recursive_mutex
COMMON: Implement Thread based on boost::thread
COMMON: Implement Condition using boost::condition_variable_any
SOUND: Add LoopingAudioStream from xoreos/ScummVM
SOUND: Add basic sound types from xoreos
SOUND: Add OpenAL SoundManager code from xoreos
MAIN: Initialize/Deinitialize the SoundManager
MAIN: Oops, move MainWindow::populateTree() back down