Hi,

as discussed with @enebo and subbu I did a the following:

• moved dot graph generation into own new module DotGraph
• created a new flag -p --pass to only dump ir after -p <pass_name>
• -h shows which <pass_name>s are available
• --f, --formatted-ir to print the IR in a concise format
  • indentation for each lexical scope like in the Ruby source code
  • line numbers for IR as in toStringInstrs()
  • The scope name is prepended
  • -i works as before
  • various require 'jruby' are merged into a single require in the beginning of the Ruby file