Clean up RMagick setup, hopefully fixing the build.

We include RMagick system-wide now since it's getting used in more and more components.

Gemfile

@@ -27,7 +27,7 @@ gem 'sqlite3'
 # gem 'jbuilder'
 
 #RMagick is used for image resizing and processing
-gem "rmagick", ">= 2.12.2"
+gem "rmagick", ">= 2.12.2", :require => 'RMagick'
 
 # Attachable does all the file work.
 gem 'attachable', '>= 0.0.2'

app/controllers/templates_controller.rb

@@ -97,8 +97,6 @@ def destroy
   # GET /template/1/preview
   # Generate a preview of the template based on the request format.
   def preview
-    require 'RMagick'
-
     @template = Template.find(params[:id])
     @media = @template.media.original.first
     @image = Magick::Image.from_blob(@media.file_contents).first

app/models/graphic.rb

@@ -21,8 +21,6 @@ def render(options={})
     # In theory, there should be more code in here to look for a cached image and be smarter
     # about the resizing, but this is a good first pass.
     if options.key?(:width) && options.key?(:height)
-      require 'RMagick'
-
       image = Magick::ImageList.new
       image.from_blob(@media.file_contents)
       image.resize!(options[:width].to_i, options[:height].to_i)