Refine mesh it DG quad exampl
Add DG quad glue grid stubs
Add local glue grids to p4est DG quad domain
Fix bug in domain output

The number of subdomains can be different on different numbers of
processors.
Add parallel glue grids to p4est DG quad domains
Remove numSubdomains^2 storage

This removes the numSubdomains^2 storage requirements from constructing
the DG quad glue grids from a p4est.
Update inter subdomain function comments
Creat boundary glue for a p4est DG quad domain