A general reaction scheme connecting lists of reactants/products defined as instances of RSPools with transitions between them which must be instances of subclasses of rsReac.
A RSCalc object is required to compute the behavior of a ReactionScheme
instance.
user interface: ReactionSchemeEditor
|     field |     type   |     contents / default value |     |
| RSPool | list | RSPool | |
| CcmbLink | list | CcmbLink | |
| RSPointProcess | list | RSPointProcess |