Fixing one more 'overloaded virtual function hidden' warning.

Refs #1777.
Merge pull request #3176 from jwpeterson/fix_warnings

Fixing one more 'overloaded virtual function hidden' warning.
modify PointValue to make it more general #3180
Merge pull request #3181 from friedmud/pointvalue_3180

modify PointValue to make it more general
Issue #3163. Added onMeshChanged().
Merge pull request #3177 from snschune/feature_3163

Issue #3163. Added onMeshChanged() and changed meshChanged() back to non...
Merge commit 'a8c076a57dee0aab973bc88f0ef9110abe2ff6e7'