Vars refactored
merge storage branch
all tests pass again
test integer adding to double is ok
grrr... broken json reading
fixed json parsing
WIP: Refactored ProcessODE to have nicer syntax for defining derivatives
TsvWriter now accepts an optional column delimiter (by default "\t")
WIP: commented out method Var[T] in Process to let ProcessODE use proper Vars instead of VarHs
commented out arithmetic methods from Var and State (we don't really need State.- afaict)