Command refactor

[pelikhan]

Reactor to use commands

$ node built/cli.js --help
Usage: cli [options] [command]

Options:
  -V, --version             output the version number
  -h, --help                display help for command

Commands:
  build [options]           build project
  download [options] <URL>  download project from share URL
  bump [options]            bump version in pxt.json and git
  init [options] [editor]   initializes the project, optionally for a
                            particular editor
  help [command]            display help for command

$ node built/cli.js help build
Usage: cli build [options]

build project

Options:
  --colors                  force color output
  --no-colors               disable color output
  --debug                   enable debug output from PXT
  -n, --native              compile native (default)
  -d, --deploy              copy resulting binary to UF2 or HEX drive
  -h, --hw <id,...>         set hardware(s) for which to compile (implies -n) 
  -j, --java-script         compile to JavaScript
  -u, --update              check for web-app updates
  -c, --config-path <file>  set configuration file path (default: "mkc.json") 
  -r, --mono-repo           also build all subfolders with 'pxt.json' in them 
  --always-built            always generate files in built/ folder (and not   
                            built/hw-variant/)
  -m, --pxt-modules         write pxt_modules/*
  --symlink-pxt-modules     symlink files in pxt_modules/* for
                            auto-completion
  --link-pxt-modules        write pxt_modules/* adhering to 'links' field in  
                            mkc.json (for pxt cli build)
  --help                    display help for command

$ node built/cli.js help download
Usage: cli download [options] <URL>

download project from share URL

Options:
  --colors     force color output
  --no-colors  disable color output
  --debug      enable debug output from PXT
  -h, --help   display help for command

$ node built/cli.js help bump
Usage: cli bump [options]

bump version in pxt.json and git

Options:
  --colors     force color output
  --no-colors  disable color output
  --debug      enable debug output from PXT
  -h, --help   display help for command

$ node built/cli.js help init
Usage: cli init [options] [editor]

initializes the project, optionally for a particular editor

Options:
  --colors     force color output
  --no-colors  disable color output
  --debug      enable debug output from PXT
  -h, --help   display help for command