Fixed an error in IdealMolalSoln -> density wasn't beeing recalculated.
Updated the test problem with the fix.
Worked CANTERA_DEBUG_MODE into the Makefiles. It wasn't being used.
Split the multiproblem DH_graph_1 test into multiple directories, one per test
Worked on getting all of the test problems to have the same look, feel, and printout.
does, putting in doxygen documentation. Tried to fix some holes
in DebyeHuckel wherein calculations may be returned without
updating the underlying water standard state.
