TS: add TSRHSJacobianSetReuse, fixes TSComputeRHSJacobianConstant

When using a constant RHS and no IJacobian, the RHS Jacobian is shifted
to make it function as an IJacobian (shift*I - Arhs), which is the matrix
used by SNES.  We don't want to duplicate the full matrix because that
uses a lot of memory, so we play this game of recording the shift and
scale, then unshifting in TSComputeRHSJacobian.  Add tests that fail
prior to this bug fix.
TS tests/ex5*: re-activate test and fix monitor interval

The test was broken in 605b8b3063496ded55fa9a when support for periodic
monitoring was removed.
TS tests/ex3: fix example and inclusion in nightlies
TS: fix shortcut scaling; document TSComputeIJacobianConstant limitations

The shortcut re-shifting on re-evaluation of the IJacobian can only be
used when the implicit system is just the "mass matrix".  This
re-scaling also needs to be recorded for the next iteration.  Since this
logic cannot work in general, it is now moved to
TSComputeIJacobianConstant.  This funtion seems to be of limited use
beyond "explicit" finite element computations (especially those that use
a consistent mass matrix) and similar.
TS tests/ex3: SNESFD and TSComputeIJacobianConstant are incompatible
TS: fix MSVC compiler error: non-POD member of anonymous struct

Suggested-by: Jed Brown <jedbrown@mcs.anl.gov>
ABI compatibility for debug and optimized builds
Merge branch 'dalcinl/libpetsc-abi' into maint
doc: add petsctime.h to SOURCEH (fixes missing docs)

Noticed-by: Richard Katz <Richard.Katz@earth.ox.ac.uk>
scalapack: add backup tarball url
X is listed as a required dependency of Zoltan but it is only optional
Merge branch 'jed/fix-ts-jacobian-linear' into maint

* jed/fix-ts-jacobian-linear:
  TS: fix MSVC compiler error: non-POD member of anonymous struct
  TS tests/ex3: SNESFD and TSComputeIJacobianConstant are incompatible
  TS: fix shortcut scaling; document TSComputeIJacobianConstant limitations
  TS tests/ex3: fix example and inclusion in nightlies
  TS tests/ex5*: re-activate test and fix monitor interval
  TS: add TSRHSJacobianSetReuse, fixes TSComputeRHSJacobianConstant
PCMG: Fixed Fortran binding
- Jed, don't you test before checkin :)
Updated DM test ex7.c to use valid command-line options to specify 2D and 3D grids.