Add test for autoloading of missing constants during yaml load.

Verified this works on ruby 1.9.3 and 2.0.0.

Part of #535
Fixed bad reference to @display variable

This was causing test output contamination where the controller
was being inspected in the output

For example, with spec/controllers/vm_common_spec.rb:32
Before:

    VmOrTemplateController
      #snap_pressed
    #<VmOrTemplateController:0x007f949fa96a10>    when snapshot is selected center toolbars are replaced

After

    VmOrTemplateController
      #snap_pressed
        when snapshot is selected center toolbars are replaced
Merge pull request #728 from jrafanie/add_test_that_missing_constants_during_yaml_load_are_autoloaded

Add test for autoloading of missing constants during yaml load.
Merge pull request #733 from Fryguy/fix_test_output_error

Fixed bad reference to @display variable