info locals and info args

Prints the name and value of local variables and function arguments.

Also fixes an issue with EvalSymbol where it could find entries outside of the intended parent info entry. 
It seems like `depth` is only being kept track of to ensure we return a meaningful error if we get through the entire section without finding the entry (i.e. we are back at the top level but have reached a null entry), however that should already be handled by the loop termination returning the error at the end of the function.