Move application from root into libdir, first step in splitting app into several.
Move dot file gen script.
Add top level rebar.config
Split core into separate app.
Move tests and related source for common functionalities to mtree_core.
Small cleanup.
Silence test ouput.
Rename merkle_tree app to mtree_server.
Strengthen test by using fake callback.

Make assumption that tests do not use the client module callbacks
explicit by passing 'undefined' as client module.
Add the first test of handshake over TCP - not complete.
Use {packet, 4} instead of my homemade framing - makes everything much cleaner.
Add working handshake test over tcp.
Remove warnings.