Make code compatible with PETSc 3.5.

 * PETSc installation instructions in the README are for v3.5.
 * Change DMDABoundaryType to DMBoundaryType.
 * Change DMDA_ to DM_ for boundary types.
 * Add new flags to CXX_FLAGS when compiling cpp files.
 * Add return statements to functions that return a value.
 * Remove parameter SAME_PRECONDITIONER from KSPSetOperators.
 * Change DMDALocalToLocal commands to DMLocalToLocal.
Merge branch 'develop' into petsc-3.5-compatible
Merge branch 'develop' into petsc-3.5-compatible
Merge branch 'develop' into petsc-3.5-compatible
Merge branch 'develop' into petsc-3.5-compatible
Update gold solution for TairaColonius test.

 * Slightly different from the solution obtained using PETSc 3.4.
 * Normalized difference in solution was 7e-4, higher than 5e-4.
Merge branch 'petsc-3.5-compatible' into develop
Update gold solution for TairaColonius test.

* Slightly different from the solution obtained using PETSc 3.4.
* Normalized difference in solution was 7e-4, higher than 5e-4.
* Don't know why the files were not updated the previous time.
Update README.