add a new material model and cookbook with reactions between compositional fields
Merge pull request #1 from jdannberg/composition-reaction

add a new material model and cookbook with reactions between composition...
Add figures.
Change composition-reaction.prm to the one used to create the figures.
Merge pull request #1 from gassmoeller/composition_reaction

Composition reaction
write a section in the manual for the composition reaction cookbook
fix some typos
update changes.h
add a test for the composition reaction
Merge pull request #16 from jdannberg/composition-reaction

Composition reaction