Adds url to platform feature
Check all p2 sites defined in the preferences 

when showing discovery ui
make default update site url http://update.bioclipse.net
Enable auto update on startup

Hack to set default value to enable auto updates
on startup.
solves bug 3554
Implements use of more than one image in Browser extractor view

Also fixes bug 3558
Fix logging and exception handling
Make Cheminformatics the default perspective on startup

Works only on new workspaces
Override PrintAction from swtjasperviewer

To make the print button work for macosx cocoa
it was necessary to add a check if the platform was cocoa

solves bug 3556