Added the wizard for links
Merging and adding more functionality with wizard

Conflicts:
	gui/CanvasController.py
The wizard function is now called on Right Click
Changes link storage object to a dictionary.  This enables us to get model info based on links in the link connection dialog box.
Added to the wizard, also have a frame that pops up.
Modifications to the wizard so that data can be passed between panels.  Added underlying link creation functionality (i.e. cmd).  Visual appeal still lacking.
Added a more visually pleasing icon set to the toolbar
Added to the wizard, fixed some errors with pypng lib. Added Matplotlib.
Removed "Add Link button from wizard.  Using the "Next" button instead.  The "Next" button is activated/deactivated using publisher/subscriber calls
Refactored the code for sharing selected link exchange items with the details panel in the wizard.
Modified link creation so that it doesn't break when a non-rectangle is selected.
Changes to the wizard, sizing issues with Matplotlib discovered. Fixing
LinkStart.
Merge branch 'dev' of https://github.com/Castronova/EMIT into dev

Conflicts:
	gui/LinkWizard.py
Changing the mouse cursor after a link is created.  The Navbar button is still not being toggled correctly.
Merge branch 'dev' of https://github.com/Castronova/EMIT into dev
fixed the sizing problem with the wizard
Added context menus
Merge branch 'dev' of https://github.com/Castronova/EMIT into dev
included add and remove link functionality to context menus.
Fixed error that occurred when loading the wizard on mac.  Enabled the "Run" button.