Added `substring` implementation, also bumped preallocated plot values up.
Renaming plot_get_env to plot_get_global_env to avoid confusion with plot_env_get
Removing nested switch from eval_func_call as no symbols were ever returned by the first eval_expr, and if they were then that would be a literal and not a valid function call
Updating implementation notes and todo
Adding basic pair datatype, temporarily disabling unimplemented string integration tests.
Breaking up integration unit tests into separate sections
Bumping gc initial allocation back down
Starting work on api changes; aiming to centralise value creation logic.
Disabling unit testing for unimplemented string procedures
Updating character procedures to use new api
Updating pair to use new api
Migrating string procedures to new api
Updating number procedures to use new value creation api
Updating funcs procedures to use new value creation api
updating number.c documentation to include scheme runtime name
updating readme to reflect move of integration tests
Updating comments in number.h
Updating funcs comments to include scheme bindings
Small doc update
Fixing additional warning under -O3