- Trying to free memory wherever possible, following where Valgrind leads.

parcel.cpp:
- Added cleanup_pipes
- Acually used cleanup_parcel

receiver.cpp:
sender.cpp:
- Added a few memsets to zero out memory to make Valgrind happy

udpipe_threads.cpp:
- Valgrind identified that the indata and outdata buffers are hanging around, so added a bunch of frees to try and make sure it's gone (not working)
- Some indentation prettification