Nora Abi Akar authored 5 years ago and Benjamin Cumming committed 5 years ago

Add modcc support for processing `CONSERVE` statements in `KINETIC` blocks.

The `KineticRewriter` remains unchanged. The `SparseSolverVisitor` is modified. 
If one or more `CONSERVE` statements are present, corresponding rows in the symbolic matrix, which would otherwise represent differential equations, are replaced by the content of the conserve statements. 

Addresses #828 and #830