merge revision(s) 39636,39741,40454: [Backport #8071] [Backport #8387]

	configure.in: suppress error messages

	* configure.in: suppress error messages, rm: cannot remove
  'conftest.dSYM', from AC_EGREP_CPP with CFLAGS=-g on Darwin.
	* configure.in (rm, shvar_to_cpp, unexpand_shvar): local is not
	  available on old shells.

	* configure.in (shvar_to_cpp): escape quotes for old shells.
	  [Bug #7959] [Bug #8071]

	* configure.in (RUBY_RM_RECURSIVE): this hack is needed by only
	  autoconf 2.69 or earlier on darwin.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@40647 b2dd03c8-39d4-4d8f-98ff-823fe69b080e