DMLabel ex1: Fix ephemeral test

DMLabel: Fix copying of ephemeral labels

Plex: DMPlexCreateEphemeral() needs to take a prefix argument
- It calls DMSetFromOptions() and also creates the DM, so we need a chance to set a prefix

Add PetscCheck() and PetscCheckA() for Fortran

Also fix incorrect use of " in Fortran examples that should be '

Fix PetscCallMPI(MPI_Allreduce()) with PETSc types

Format the ftn-custom files with clang-format. Apparently no particular reason we did not format them initially

Fix some documentation and typos

More manual page fixes

Remove need for seperate lib/petsc/conf/test file by merging with rules file

Commit-type: maintainability

non-test and tutorial makefiles only need rules.doc not the full rules

Commit-type: documentation

Only makefiles in the test and tutorial directories need lib/petsc/conf/test

Commit-type: housekeeping