Added support for maxDestLen < maxCompressedLength to the JNI HC compressor.

Close #17
Fixed ArrayIndexOutOfBoundsException in the Java HC compressors on highly compressible inputs when srcOff is > 0.

Close #12.
Update changelog.
Added utility methods that take and return (de)compressed byte[]s.

Close #18
Maintain backward compatibility in LZ4Factory.
Re-enable some disabled tests.