Organise build process a bit

1. It copy its content to root of final jar
2. Add support to watch changes (via `~`)

Additionally i added part of dist plugin. It adds command `package-dist`:

1. It add manifest entries about main class, classpath.
2. Copy all dependencies to dist/lib
3. Zip jar and dependencies in one distributable archive.

So you will can just run it will `java --jar your_jar` and it will 'just work'. I prefer such way others that create uber-jars and plays with class loaders.