Add simple server for prototyping inspired by handlebars-proto

[giflw]

Add a simple server for prototyping.

• -h or --help show simple help message
• --port set port to run, or run on 4567 if not given
• use current directory or given one to serve files
• file to serve is given in url
• if a yml or json file with same name as template exists, it is used as model in rendering
• to access a file called "foo.jade" use http://localhost:4567/foo
• to access a file called "bar.jade" in a directory called "foo" use http://localhost:4567/foo/bar

I've added a profile called jade4j-proto to execute appassembler plugin to create a distributable folder