* master: (270 commits)
  Mild refactoring of invokers code (came from bytelist_love work).  As I need to make changes to generated code I am trying to comment/document some portions and reduce some duplication when possible.
  resolve regression with Set impl - SortedSet did not clone/dup properly
  be explicit about non-happening exception + avoid dynamic ** call
  cleanup Rational - use RubyInteger#idiv so we're no hitting call-sites
  introduce long overloads for common (integer) ops + start using them
  raise ArgumentError
  use encoding none for n/N option
  fix IOOBE in test_regexp quote
  Fix documents
  Revise COPYRIGHT YEAR
  use num2int in StringIO#ungetc
  Fix a typo
  Remove not used methods (jruby#4973)
  Inline the regexp validation inside ParserSupport
  Simplify the regexp validation logic
  Add support for validating Regexp in Ripper
  Make sure to clear $! when rescuing RaiseException
  Align validation code with MRI
  Move Regexp checking from ParserSupport to Lexer
  Extract parseRegexpFlags to Lexer
  ...