* lib/rubygems/commands/setup_command.rb:  Don't delete non-rubygems
  files when installing RubyGems.
* test/rubygems/test_gem_commands_setup_command.rb:  Test for the
  above.

* lib/rubygems/ext/ext_conf_builder.rb:  Use full path to siteconf.rb
  in case the extconf.rb changes directories (like memcached does).

* lib/rubygems/package.rb:  Remove double slash from path.
* test/rubygems/test_gem_package.rb:  Test for the above.
* test/rubygems/test_gem_package_old.rb:  ditto.

* lib/rubygems/source.rb:  Revert automatic HTTPS upgrade
* lib/rubygems/spec_fetcher.rb:  ditto.
* test/rubygems/test_gem_remote_fetcher.rb:  ditto.
* test/rubygems/test_gem_source.rb:  ditto.
* test/rubygems/test_gem_spec_fetcher.rb:  ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39731 b2dd03c8-39d4-4d8f-98ff-823fe69b080e