merge revision(s) 42862(partially),42910,43093: [Backport #8878] [Backport #9085]

	* common.mk: use RUNRUBY instead of MINIRUBY because MINIRUBY can't
	  require extension libraries. The patch is from nobu
	  (Nobuyoshi Nakada).

	* configure.in (RUNRUBY): append -- only after runruby.rb, not
	  cross-compiling baseruby, so that $(RUN_OPT) can be command line
	  options.  [ruby-dev:47703] [Bug #8893]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@43654 b2dd03c8-39d4-4d8f-98ff-823fe69b080e