column virtualization prototype.
attempting improvements to virtualization.
doing some code optimizations.
adding column building on resize

fixing bug when grouping while scrolled.
fixing aggregate display.
major changes to accomoodate column virt.
adding and fixing lots of stuff.

adding heavyVirt mode for columns
adding custom input directive for the default edit template
adding support for #173
demorgan crap :(
changing sorting to use $parse.
Merge branch 'master' of https://github.com/angular-ui/ng-grid into colvirt
Merge branch 'master' of https://github.com/angular-ui/ng-grid into colvirt
merge master, rebuild
Fixing selections
cell navigation works now.
fixing a comment
trying to get cell nav to work with column virtualization
cell nav works in reverse...
aha!
Fixed cell navigtion issues with column virtualization.