Moved project files to subdirectory dnclient

The project was moved to the subdirectory dnclient so that a new project
for the server (dnserver) can be created. The project's directories all
refer to dnclient now instead of diynote, so namespaces and other
references to diynote will need to be replaced in the current code with
dnclient. A new top level README and LICENSE will need to be added to
the root directory of the repository as well.
Added lein 'app' template for dnserver
Changed references s/diynote/dnclient/g

The project for the client side application is dnclient, so all
references to namespaces, filepaths etc. have been changed
appropriately.
Move LICENSE to top directory level of repository

The LICENSE file in dnserver/ has been deleted so that there is a single
file at the top level to refer to that applies to both dnclient and
dnserver. README.md for dnserver has also been updated to use The MIT
License.