Added docs folder

with notes about the requirements for the client daemon and the ui.
updated documentation + moved into a /doc folder
updated client daemon documentation about /tmp and UIs
minimal documentation on reducing the character set of dename names
Merge branch 'master' of github.com:andres-erbsen/chatterbox into server
There's still a bug if you run go test several times quickly in succession. Message uploading is tested, though.