Enable VTK module vtkParallelCore

ProtoCall requires vtkParallelCore for communication.

Change-Id: I6e658301a2e36c3f9ac6f5e2bd3e80f6284d038d
Add protobuf as a submodule

Change-Id: I465ea33568e2723512a48081000dc29f90e9e8e6
Add protocall as submodule

Change-Id: I711f72f82c8e2d0f3f158b49254bf32372a5f4db
Add protobuf and ProtoCall to super-build

Change-Id: I283bafe8e899585a24909ea7cef93c19cb6a1034
Move protobuf and ProtoCall submodules forward

Move submodules forward to include fixes for
building against installed versions.

Change-Id: Ic414267c29cd232bafc8b57f660428c66ae4db7d
Add protobuf dependency to protocall

Change-Id: Icf014a5c2b2b454a85236c1268aab8ad32a5ccb3
Merge topic 'add-protocall' into master

7a6cee61 Add protobuf dependency to protocall
bf4fd31d Move protobuf and ProtoCall submodules forward
8e3bf505 Add protobuf and ProtoCall to super-build
3743325b Add protocall as submodule
223888cd Add protobuf as a submodule
e931fe23 Enable VTK module vtkParallelCore