Merge pull request #389 from sappo/master

zprotocol - simple protocol/api
Rebuilt man pages
Added zchunk_append method
Allow NULL path on constructor
Problem: need to serialize ZPL to/from memory

- added zconfig_save_chunk and _load_chunk
- zconfig_load now loads entire ZPL file into a chunk and then calls
  the chunk parser.
Merge pull request #390 from hintjens/master

Added ZPL serialization to/from memory
Merge branch 'master' of github.com:zeromq/czmq