Tables can now be frozen, so that model rebuilds and filters do not take...

Tables can now be frozen, so that model rebuilds and filters do not take effect until unfrozen.  This is especially usefull when editing values in the table that you are currently filtering on.  For example, if you have filtered to see only edit-locked points with a certain number of measures, and then plan to remove some of the locks, it is nice to not have the points disappear as soon as the locks are removed.  Having them stick around until you are done editing allows you to edit other attributes of the point, and provides context for where you are in the editing process.  Future work is planned to further polish this feature.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@3165 41f8697f-d340-4b68-9986-7bafba869bb8