* lib/rubygems:  Update to RubyGems 2.1.3

  Fixed installing platform gems

  Restored concurrent requires

  Fixed installing gems with extensions with --install-dir

  Fixed `gem fetch -v` to install the latest version

  Fixed installing gems with "./" in their files entries

* test/rubygems/test_gem_package.rb:  Tests for the above.

* NEWS:  Updated for RubyGems 2.1.3


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42938 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-09-14

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42939 b2dd03c8-39d4-4d8f-98ff-823fe69b080e