Fixed a problem with byte switching

This fixes an issue with byte switching. The preprocessor directive
used to determine the endianess of the system only worked on Linux
resulting in voice running over TCP only when umurmur runs on other
platforms. Note, this patch could and should be implemented better
but is working and should be regarded as a hotfix.
Cleanup of the byteorder patch

This version of the patch, while technically the same, is a little
cleaner in code. It seems to be working on NetBSD, MOX and Linux.
Fixed license notice

Added Martin and Thorvald since most of the code is actually from
them.
Merge pull request #38 from fmorgner/master

Byte order fix for BSD and OSX