COMMON: Add BitStream from xoreos
COMMON: Add Huffman from xoreos
COMMON: Add maths.h/maths.cpp from xoreos
COMMON: Add static sine window tables from xoreos
COMMON: Add static cosine tables from xoreos
COMMON: Add FFT code from xoreos, based on FFmpeg

(Inverse) Fast Fourier Transform.
COMMON: Add MDCT code from xoreos, based on FFmpeg

(Inverse) Modified Discrete Cosine Transform.
SOUND: Add AudioStream from xoreos/ScummVM
SOUND: Add audio decoders from xoreos/ScummVM

WAVE
PCM
ADPCM
ASF
WMA
MP3
VORBIS
SOUND: Add a stubby SoundManager

Right now, it only creates AudioStreams from SeekableReadStreams.
MAIN: Add MainWindow::dialogOpenDir()
MAIN: Add MainWindow::dialogOpenFile()
MAIN: Add MainWindow::dialogSaveFile()
MAIN: Let all sounds be exported as PCM WAV