Grid layout of slide: MxN cells

Example with a bullet list to the left and a figure to the right (two cells: 00 and 01): 

!split
===== Headline =====

!bslidecell 00
!bpop
 * Key point 1
 * Key point 2
 * Key point 3
!epop

!bpop
!bt
\[ -\nabla^2 u = f \quad\hbox{in }\Omega \]
!et
!epop

!eslidecell

!bslidecell 01
FIGURE: [fig/broken_pen_and_paper, width=400 frac=0.8]
!eslidecell

!split
===== Next slide... =====