Adding PETSC_CC_INCLUDES to PETSCINCLUDEDIRS

This fixes the case where MPI gets snooped from PETSc, but PETSc was
using mpicc-type compiler wrappers and we're trying to use a different
compiler instead.
Don't bother with an extra function call for querying SCALAR values
until/unless we actually see SCALAR values that need to be set.
Adding --host as an option to libmesh-config.
Ignore autotools installation directories.
Allow VariableGroup to group scalar variables together
Get the right variable name when querying SCALARs

via a wrapped function
Merge pull request #31 from andrsd/var-group

Allow VariableGroup to group scalar variables together
Merge branch 'master' of github.com:libMesh/libmesh
TOLERANCE would be namespaced and easier to debug with if it was a
static const rather than a macro
Add a "make coverage" target for gcov/lcov output.

Thanks to Paul Bauman for figuring this all out.

Looks like we're only getting 30-40% coverage from "make check" at present.
Add getpot_parse utility for debugging purposes
Add GetPot Dollar-Bracket-Expression functions

Now you can use ${=funcname arg1 arg2} etc. for cmath functions
(except for pow and exp, already covered well enough by ^) and
cstdlib rand/srand functions.
Clean up gcov outputs during "make clean"
Merge pull request #29 from robert-we/master

Callback for monitor linear solution in newton solver
Clear the KDTree too!!!
discern whether we have been installed or not
link external-facing ExodusII files into include/libmesh
set back to executable
fix for no nanoflann
make building from a tarball work in the top-level