merge revision(s) 36948,41777,41779 [Backport #8593]

	* lib/mkmf.rb (have_framework): insert a space between options.
	  add just one -ObjC option.

	* lib/mkmf.rb (have_framework): allow header file to check.
	  [ruby-core:55745] [Bug #8593]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@42550 b2dd03c8-39d4-4d8f-98ff-823fe69b080e