Disable properties action in menu

* Properties action is now activated in context menu iff the selected
* edit part has installed AbstractPerfCakeComponentEditPolicy
Show properties copy in generator preferences.
Use propertyModel in generator wizard
Show properties in generator

Edit properties in generator disabled.
Introduce IPropertyContainer interface
Extend Properties edit policies and commands

* Use IPropertyContainer in policies and commands to easily reuse same
* commands for different property containers
Split renameProperty command to two commands
Allow to edit properties in generator properties
Fix fire property change  when setting property value
Introduce API for managing editing support in wizard using GEF commands
Fix Generator wizard to contain RunModel
Add comments
Extract property viewer from Generator page to separate type
Fix editing run value using wizard
Extend PerfCakePage API

Add edit mode variable
Add methods for fill in values
Extend sender page to accept properties
Refactor selection in combo
Do not override performCancel()

It is already implemented in superclass
Move getCommand to superclass
Undo editing support commands in superclass performFinish()