Update filters to accept decompressed size in reset() function

This makes them work with the recent change in libgamecommon.
Zone 66: Implement (fake) compression

This is only fake compression, in that the data is not made smaller, it is just
encoded such that the game will recover the original data when it tries to
decompress it.
Zone 66: Fix bug in decompression

The input stream would drop a byte if it was too close to the end of the read
buffer, corrupting all data following that point.