valgrind creeping into makefiles

[Barry Smith]

    I noticed valgrind commands creeping into PETSc example makefiles.  
I believe this is a terrible model and would like to remove them.

    I've added support for calling valgrind correctly from linux or  
the Mac to $PETSC_DIR/bin/petscmpiexec as an optional first argument - 
valgrind.
Thus you can call any PETSc program with valgrind using, for example,  
petscmpiexec -valgrind -n 2 ./ex1 -ksp_monitor

    Now for makefile tests one can run, for example: make runex7  
MPEXEC="petscmpiexec -valgrind" and it will run the runex7 test under  
valgrind.
Is this an acceptable replacement for having all the horrible  
redundant use of valgrind directly in the makefiles and do I have  
everyones permission to remove the use of valgrind from the makefiles?  
If not, what support do I need to add to get rid of the use of  
valgrind from the makefiles?


    Barry