MohrCoulombExponential added and MohrCoulomb tests modified accordingly

MohrCoulombCubic added, and a test showing its correctness

Fixes #3965
WeakPlaneTensile now has strength = 1, and
WeakPlaneTensileCubic has cubic hardening/softening, and
WeakPlaneTensileExponential has exponential hardening/softening

Test files modified accordingly, and a test of the Cubic version included

(This commit also includes some changes needed by a rebase from upstream)

This addresses #3965 , but does not completely fix it, but it's convenient
to request a merge now in order to work on other related things
A working version of PBS functionality. Still need to tally launches correctly. References #4114
Using jacobian caching in computeFullJacobianThread

Removing ComputeFullJacobianThread::postElement, thus using its parent's
implementation that has jacobian caching. Also, added caching of
contributions coming from scalar variables.
Moving the if-statement in DGKernel outside computeOffDiagJacobian

It was inside the most inner loop, but it should be outside
(performance!).
Fixing a typo
Do not check the emptiness of DGKernelWarehouse 3 times.

Once is just enough ;-)
Merge pull request #4112 from WilkAndy/rework_harden_3965

Rework harden 3965
Added missing call to prepareFaceShapes

This was causing an issue in a threaded run, where the shape function
values were not computed and the jacobian contribution ended up being
zero.

Closes #4109
Removing abandoned input file

This file seems to be in tests/userobjects/side_user_object_boundary_id
Running the test only with 1 thread

The test seems to be stable, but with 4 threads, it sometimes gives a
slightly different answer (~ 1e-2 rel. tolerance). This might be caused
just by different order of floating point operations, because the test
would sometime pass even with 4 threads.  However, marking it just for
serial runs.
Don't use CLI overrides in subapps
closes #4117
Merge commit 'd9d2e07baf66c3a627e8540a1f6cfed871f67e48'
Merge pull request #4115 from milljm/pbs_fix

A working version of PBS functionality
Merge pull request #4116 from andrsd/jacobian-threading-issue

Fixing various issues
Default Transfer execute_on to match associated Multiapp
closes #4001
Merge commit '6ade0039fb10c3f0e6c67389ffb41b8234716043'
Merge pull request #4118 from permcody/cli_sub_app_override

Don't use CLI overrides in subapps
Merge commit 'fcc6b4123ef784ffd71b833e61564d0c09d124e5'
Merge commit '281be38b95c6b38f927688a270e4e5294f2a9466'