Let's use $CXXFLAGS if $libmesh_CXXFLAGS isn't available.  This is helpful in case something in CXXFLAGS is particularly important - a missing -DMPICH_IGNORE_CXX_SEEK just bit me.
Let's use $CXXFLAGS if $libmesh_CXXFLAGS isn't available.  This is
helpful in case something in CXXFLAGS is particularly important - a
missing -DMPICH_IGNORE_CXX_SEEK just bit me.



git-svn-id: ffc1bc5b3feaf8644044862cc38c386ade156493@3750 434f946d-2f3d-0410-ba4c-cb9f52fb0dbf

certik/libmesh,certik/libmesh,certik/libmesh,certik/libmesh,certik/libmesh,certik/libmesh,certik/libmesh