Sacn

Due to a debugging statement, the sending and receiving hot paths were slower than necessary. The debugging statements were removed and the performance improved.

Note that this means the logging output will now be different (missing messages when a packet was send or received).

See 25 for more information and thanks to shauneccles !

Fix: When creating a DataPacket with invalid DMX start codes (i.e. not `0x00`) an exception is thrown (Thanks to niggiover9000 ! See 11 for more information)

When using a manual flush, only a specified list of universes can be flushed (Thanks to CrazyIvan359 ! See 22 for more information)

The universe used for the sACN-sync messages can now be set when creating a `sACNsender` (Thanks to CrazyIvan359 ! See 21 for more information)

The sequence number of the sync-packet when using a manual flush was not increased, but it should have been.

Thanks to BlakeGarner for spoting this issue and submitting a pull-request (19) for fixing!

The internal logging of the `receiver_thread` and `output_thread` was using the root logger instead of its module-logger.

Thanks to mje-nz for the pull request solving this issue!

See 18 for more information.