title: require gem in a Redmine plugin 'init.rb' fails
body: <p>I am building a plugin for Redmine 2.0 and for the following line in plugin's 'init.rb' </p>
  
  <pre><code>require 'ice_cube'
  </code></pre>
  
  <p>I get the load error even though the 'ice_cube' is installed and show up when I do 'gem list'
  I am using rvm with ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-darwin11.2.0]</p>
  
  <p>Here is the error log:</p>
  
  <pre><code>/Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require': cannot load such file -- ice_cube (LoadError)
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `block in require'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:236:in `load_dependency'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/plugins/redmine_asset_tracker/init.rb:2:in `&lt;top (required)&gt;'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `block in require'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:236:in `load_dependency'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/lib/redmine/plugin.rb:129:in `block in load'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/lib/redmine/plugin.rb:120:in `each'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/lib/redmine/plugin.rb:120:in `load'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/config/initializers/30-redmine.rb:13:in `&lt;top (required)&gt;'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:245:in `load'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:245:in `block in load'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:236:in `load_dependency'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:245:in `load'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/engine.rb:588:in `block (2 levels) in &lt;class:Engine&gt;'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/engine.rb:587:in `each'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/engine.rb:587:in `block in &lt;class:Engine&gt;'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:30:in `instance_exec'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:30:in `run'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:55:in `block in run_initializers'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:54:in `each'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:54:in `run_initializers'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/application.rb:136:in `initialize!'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/railtie/configurable.rb:30:in `method_missing'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/config/environment.rb:14:in `&lt;top (required)&gt;'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/config.ru:4:in `require'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/config.ru:4:in `block in &lt;main&gt;'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/config.ru:1:in `new'
      from /Users/myth/Learn/Code/Berkman GSOC 2012/Berkman/redmine/config.ru:1:in `&lt;main&gt;'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:200:in `app'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands/server.rb:46:in `app'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands/server.rb:70:in `start'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands.rb:55:in `block in &lt;top (required)&gt;'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands.rb:50:in `tap'
      from /Users/myth/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands.rb:50:in `&lt;top (required)&gt;'
      from script/rails:6:in `require'
      from script/rails:6:in `&lt;main&gt;'
  </code></pre>