dmplex: Type annotate missing variable
dmplex: Correct 2d array indexing
dmplex: Declare numpy arrays with mode="c" and appropriate ndim
Merge pull request #419 from firedrakeproject/dmplex_types

* dmplex_types:
  dmplex: Declare numpy arrays with mode="c" and appropriate ndim
  dmplex: Correct 2d array indexing
  dmplex: Type annotate missing variable