Revert "Merge pull request rubygems#1364 from tpope/bundler"

This reverts commit 93942d7, reversing
changes made to 8cf9a6d.

Loading gem plugins can cause bundle install to fail.

Conflicts:

	lib/bundler/cli.rb

lib/bundler/cli.rb

@@ -213,8 +213,6 @@ def install
       Bundler.ui.be_quiet! if opts[:quiet]
 
       Bundler::Fetcher.disable_endpoint = opts["full-index"]
-      # rubygems plugins sometimes hook into the gem install process
-      Gem.load_plugins if Gem.respond_to?(:load_plugins)
 
       Installer.install(Bundler.root, Bundler.definition, opts)
       Bundler.load.cache if Bundler.root.join("vendor/cache").exist? && !options["no-cache"]
@@ -266,9 +264,6 @@ def update(*gems)
       end
 
       opts = {"update" => true, "local" => options[:local]}
-      # rubygems plugins sometimes hook into the gem install process
-      Gem.load_plugins if Gem.respond_to?(:load_plugins)
-
       Installer.install Bundler.root, Bundler.definition, opts
       Bundler.load.cache if Bundler.root.join("vendor/cache").exist?
       clean if options["clean"] && Bundler.settings[:path]