apparently fixed a overflow bug.
some fixes in using AMG 'aggregates' in GASM smoothers
fixed bug with ksp/ex56 using non-real scalars and near null space interface. Changed ex56 to use near null space in test 'make runex56'.
SNESGS: Fix for warning in the GS-Secant code.
PCKACZMARZ: Sign mistake for symmetric application
add davis2011 to src/docs/tex/petsc.bib
makefile: cleanup targets using SOURCE SOURCEALL and SOURCED
build: split cxx [legacy] build target via SOURCECXX
make: add *.cxx *.cu to relavent make targets
tests: split up C++ tests [which can run with clanguage=c with C++ compiler build]
fixed hdf5.py so that if self.libraries.compression is None the code still runs correctly
Merge branch 'barry/ts-rhsjacobian-only'
Merge branch 'barry/update-some-manualpages'
Merge branch 'barry/tao-fixes-for-petsc4py'
Merge branch 'prbrune/dm-destroylinkedlistfix'

* prbrune/dm-destroylinkedlistfix:
  DM: Fix for recursive DMDestroy() causing valgrind issues
Merge branch 'prbrune/snes-snesapplypcfix'

* prbrune/snes-snesapplypcfix:
  SNES: Removed now-extraneous fnorm variable from SNESApplyPC()

Conflicts:
	src/snes/interface/snespc.c
Merge branch 'prbrune/fas-gscolorsecant' into next

* prbrune/fas-gscolorsecant:
  SNESGS: Fix for warning in the GS-Secant code.
Merge branch 'prbrune/fas-gscolorsecant'

* prbrune/fas-gscolorsecant:
  SNESGS: Fix for warning in the GS-Secant code.
Merge branch 'prbrune/pckaczmarz' into next

* prbrune/pckaczmarz:
  PCKACZMARZ: Sign mistake for symmetric application
Merge branch 'prbrune/pckaczmarz'

* prbrune/pckaczmarz:
  PCKACZMARZ: Sign mistake for symmetric application
  PCKACZMARZ: Added symmetric application option.
  PCKACZMARZ: Added a basic Kaczmarz row-projection smoother as a PC

Conflicts:
	src/ksp/pc/impls/makefile