Fixes status message when PETSc couldn't be found.
Removes broken conditional check.

The FindPetsc module would check for a PETSC_ROOT and not attempt to look for
mpi and the petsc header if this was not set, which it in most cases won't be.
If the variable is set then the conditional include is redundant, as it will
search the explicitly passed paths first anyways.
FindPets searches default paths w/ general namings

Removed the NO_DEFAULT_PATH flag as this really isn't working for most systems
(where PETSc will be installed from a repository and in /usr or /). Path suffix
parameters extended to accept more version-less configs too, to be compatible
with a default PETSc (debian style) install.