Adds an EMF implementation of JXPath's DynamicPropertyHandler and
registers one for each workbench model class. This avoids costly bean
inspection and many class lookup failures for non-existing *BeanInfo and
*Customizer classes during Eclipse startup.

Change-Id: Ic8d5fbca15fecfb2fef94df48ed82cb962fe2798
Signed-off-by: Karsten Thoms <karsten.thoms@itemis.de>