Remove System.Drawing reference from live deployment

[lmagyar]

Designers shouldn't use attributes, generate descriptions during design time on request.

[lmagyar]

Based on these:

• https://code.msdn.microsoft.com/Windows-Workflow-9e867448
• http://stackoverflow.com/questions/15423061/wf4-runtime-attempts-to-load-loosely-coupled-activity-designer
• http://blogs.msdn.com/b/tilovell/archive/2011/05/08/iregistermetadata-and-best-practice-associating-workflow-activity-designers.aspx

None of them are working:

• When you separate the designers into a separate .Design.dll, there is no way to set icons and descriptions for the toolbox. Only the WF designer uses the IRegisterMetadata interface, the toolbox browses only the .dll where the activity is located.
• So, when you use IRegisterMetadata to add design time attributes to activities, you can't separate the ToolboxBitmapAttribute this way, you must add this to the activity, but this way the activity .dll will still have reference on System.Drawing...

Help wanted: maybe somebody knows the solution.