enabled supportsRange on font obfuscator, so we can test a real content filter. unforunately the implementation is incomplete, as RangeFilterContext is never instanciated anywhere, and FilterChainSyncStream::ReadBytes/FilterBytes() with the ByteRange parameter are never used anywhere. also, ByteRangeFilterSyncStream::ReadBytes() with the ByteRange parameter invokes FilterData() with null pointer for source buffer data, so obviously it is not going to return anything :)   (as I said, this seems incomplete at this stage...to be continued)