v3: fix automatic cmake routines for finding external libraries
the following CMAKE entries have to be modified manually:
- mkl: include
- umfpack: include, use dynamic lib instead of static
- Hypre: include and lib dir
- HDF5: include and libs
- mumps: libscalapack, libblacs, libblacs_init
- blas: lib
- lapack: lib and include
- petsc
- slepc