Added a rough matroska implementation.
CMakeLists adjusted for Matroska
Changed to/from LongLong to to/from (U)Int64
Correct length calculation
Redesigned toNumber/fromNumber API of ByteVector
Merge pull request #156 from Rachus/taglib2

A Matroska implementation
Merge branch 'taglib2' into tonumber4-merge

Conflicts:
	ConfigureChecks.cmake
	config-taglib.h.cmake
Merge pull request #172 from TsudaKageyu/tonumber4

Redesigned toNumber/fromNumber API of ByteVector