Changes

Fix form value hidden by a value in page context
Sometimes Page context resolver goes before the general resolver. 
If it contains the same property (e.g. with null value) then it hides the value in other sources. 
This fix sets the value from the form also to page context so that it's not covered.
Fixes a bug in GlassFish Admin Console for some form values.
Signed-off-by:Ondro Mihalyi <mihalyi@omnifish.ee>

Don't set value in PageSessionResolver if base == null
Signed-off-by:Ondro Mihalyi <mihalyi@omnifish.ee>