--
* ext/readline/readline.c: apply a patch from Nobuyoshi Nakada.
  fixed #3616 [ruby-core:31484] IRB + readline incorrectly counts
  non-printing characters in prompt
--
* ext/readline/extconf.rb: new checks for RL_PROMPT_START_IGNORE
  and RL_PROMPT_END_IGNORE. [ruby-core:34331]

* ext/readline/readline.c: enables USE_INSERT_IGNORE_ESCAPE only if
  RL_PROMPT_{START,END}_IGNORE are available to get rid of compilation
  error with libedit.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@30569 b2dd03c8-39d4-4d8f-98ff-823fe69b080e