[borderdofexchanger]
fix access right to typedefs in the non-overlapping case
Merge branch 'master' into feature/gridglue
[gridglueoperator]
call the extra_pattern only once
[localoperator]
improve default imp, so that it can also handle different lfs types for inside and outside
[test]
gridglue: improve local operators

- add subdomain operators
- add empty coupling operator
- add skeleton pattern
[gridglueoperator]
improve assembler to only include those skeleton terms where we actually have a coupling