Changed the way long are serialzed to byte array to be the same as ZeroMQ

The big issue with this change is that it's making old releases of NetMQ not compatible with this fix.

I was able to fix this one way (incoming to the fixed version) with checking the MSB of any long and if it different from zero reverse the array, but old versions of NetMQ receiving large messages will have a problem...

If you have a suggestion it will be great...