Set _is_closed to false whenever PETSc APIs that "unclose" a vector are called.
Set _is_closed to false whenever PETSc APIs that "unclose" a vector
are called.


git-svn-id: ffc1bc5b3feaf8644044862cc38c386ade156493@1622 434f946d-2f3d-0410-ba4c-cb9f52fb0dbf

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