GDA-5838 - Moved JythonPerspective to uk.ac.gda.client.scripting

From uk.ac.gda.pydev.extension

Includes changes to prefence handling and references to ID.
Merge branch 'pydev-3.3.3'

Conflicts:
	uk.ac.gda.client/META-INF/MANIFEST.MF
Fix MANIFEST
Add Activator class to uk.ac.gda.client

Change imports from uk.ac.pydev.extension to new Activator
Deleted pydev.extension plug-in
Change references to new Activator in uk.ac.gda.client