FMSLogo Code

Update a bug number in a comment to match the bug's current number.
When FMSLogo started, all tickets from all projects shared the number space.
Later, each project was given its own bug numbers and all existing bugs were renumbered to be much smaller.
External references to the larger bug numbers were not updated.

Rework proc_name_arg:
- Remove the side effect of modifying the argument list.
- Change it to accept the argument, not the argument list.
- Make it intern the argument name, since all callers did that.
- Rename to intern_proc_name_arg to reflect the new behavior.

Add more bad input tests for ARITY to prepare for some refactoring of proc_name_arg().

Rewrite proc_name_arg() in terms of validate_argument().
This is a step toward removing the side effect of modifying the arguments list.
Unfortunately, this required making IS_VALID_ARGUMENT accept a non-const NODE* because numberp() modifies its input.

Fix Bug #612; COPYDEF of procedure defined with DEFINE now has the correct title line.

Change mustDerefStringnode to mustGcrefStringnode in numberp().
A ref and a deref are not necessary. A simple gcref suffices.
Unfortunately, the flag is still needed because numberp's argument may not have any references.

Add a missing line break

Refactoring: Change lbutlast to use CAppendableList.
This reduces code duplication.

Rework char_arg to take the argument instead of an argument list.
Also, rename it to validate_char_argument since it follows the new conventions of the validate* functions.

Refactoring: Change the signature of char_arg() to return a wchar_t instead of NODE*.
This is what all of the callers want, anyway.

This change makes it clear that char_arg() is responsible for freeing whatever it allocates.