Multiple Content Filter support (iteration + correct byte buffer passing)
see https://github.com/readium/readium-sdk/issues/147
Includes: zero'ed buffer in Filter Context for byte ranges, explicit type cast for seekable byte stream in non-range Content Filter, fixed memory free() in media decryption with byte-range support, refactored vector of pairs (generic tuple) in favour or 2x aligned vectors of concrete types (Filter + FilterContext), removed duplicate / unused method signatures, harmonised tab vs. spaces.
not sure why my previous commit removed the line breaks at end of file...restoring them
addresses https://github.com/readium/readium-sdk/issues/148
(ItemProperties::None, HasProperty handling)
iCustom-namespaced metadata support in OPF https://github.com/readium/readium-sdk/issues/149
addresses https://github.com/readium/SDKLauncher-OSX/issues/37 to match OSX launcher app
Merge branch 'develop' into feature/AndroidByteRangeStream