Get GridView branch compiling on Linux/GCC

This does not yet have the fix or test for the template issue
@evanweaver was discussing.
Get OSGridController templates compiling

Needed to templatize the return type, since you are trying to return
something specific (ThermalZone) into something generic (ModelObject).

All of the previous examples that I worked on with Kyle were always
returning something specific (int, bool, etc).

Not a big deal or difficult, and I was able to clean up the call to the
addColumn function by dropping the template parameters as well.

@kbenne should probably review to make sure that it's still doing what
he intended it to do, but I believe it is.

@evanweaver.