Changed toleranceKeepInEdge, which was initially a flux, into a ratio of edge rate against characteristic rate!

A unitless tolerance makes more sense than flux.
Minor import fix in makeProfileGraph funciton.

Fixes problem of gprof2dot getting imported as a module rather than a class.
Reduced the unnecessary calls to calculateSymmetryNumber when calculating radical thermo.

calculateSymmetryNumber for saturated structure was called too frequently
when calculating entropy of radical.
Add decrement lone pair atomtypes for 'C' and 'Cs' atomtypes.

For reactions with carbene or carbon atom.