Merge branch 'fc/ruby' into integration

Merge branch 'fc/ruby' into integration

* fc/ruby:
  ruby: add simpler option parser
  ruby: add useful helpers
  ruby: bind log_tree_diff_flush()
  ruby: bind diff_tree_sha1()
  ruby: bind shortlog()
  ruby: add RevInfo and DiffOptions
  shortlog: split builtin from common code
  shortlog: add missing declaration
  ruby: bind read_sha1_file()
  ruby: bind find_unique_abbrev()
  ruby: bind remote and transport stuff
  ruby: bind get_merge_bases()
  ruby: add Commit class
  ruby: bind get_sha1()
  ruby: bind read_ref()/peel_ref()
  ruby: bind git_config()
  ruby: bind dwim_ref()
  ruby: bind setup_git_directory()
  ruby: add support for internal ruby programs
  Add support for ruby commands