Feature/ws cli (#15)

* New command line tool for transfering files / still very beta.

* add readme

* use cli11 for argument parsing

* json -> msgpack

* stop using base64 and use binary which can be stored in message pack

third_party/remove_trailing_whitespaces.sh

@@ -0,0 +1,2 @@
+find . -type f -name '*.cpp' -exec sed -i '' 's/[[:space:]]*$//' {} \+
+find . -type f -name '*.h' -exec sed -i '' 's/[[:space:]]*$//' {} \+