AmberCli: new package combining FileServer and REPL in one tool
update bin/amber to use the new AmberCli (retain old behavior)
update bin/server to use the new AmberCli (retain old behavior)
remove repl directory in favor of the cli package
remove server directory in favor of the cli package
Gruntfile: remove targets for repl and server; add target for AmberCli
cli: rename 'amber server' to 'amber serve'
cli: class comments for Repl
FileServer: add class documentation
FileServer: remove unused >>username:password: method

This method also does not work with the commandline parameter handling
AmberCli: add class comment
AmberCli: not existing commands now print the help message
Merge pull request #474 from mkroehnert/cli

Create AmberCli package containing FileServer and Repl