Handling pointers
Using tree_preorder for build_symbols

Refactored to conditionally recurse on children based on return value of
applied function.
Adding STATEMENT_SEQ1 rule to avoid collapse in functions

We always want a function to be a list of statements, even if it is just
one statement.
Cleaning up typeinfo_delete function
Adding handle_node rule handler (applied via preorder traversal)
Adding parameter list handlers for function definitions
Adding list forward declaration
Cleaning up whitespace
Refactoring insert_symbol
Fixing bug in typeinfo_new() thanks to missing breaks in switch
Adding type comparators for prototype handling
Refactoring handle_node() to use rules instead of sizes
Better handling of prototype parameters
Updating TODO list