FMSLogo Code

Add missing "const" qualifier to CanCut and CanCopy so that they override the virtual functions in wxTextCtrl.
This required a little rework to a helper function IsTextSelected() to make it const, as well.
This fixes two -Woverloaded-virtual warnings in gcc.

Refactoring: Change "int macro_flag" to "bool is_macro" in define_helper.
The caller that passed the third state of -1 now calls make_procnode_from_body_list().
This makes the code simpler.

Refactoring: Extract make_procnode_from_body_list() from define_helper.
It is the only portion of define_helper() that anonymous_function uses.
This is a step toward removing the tristate "int macro_flag" from define_helper.

Refactoring of define_helper:
- add clear variable names instead of reusing args, arg, and val.
- move variable definitons to where they're used
- restructure into three major parts

This moves the code closer to being able to get rid of the tristate macro_flag.

Add more regression tests for DEFINE.
This was done to prepare for some refactoring in define_helper().

Replace TRUE with 1 and FALSE with 0.
In this case, the value isn't treated as a boolean, so it's not correct to use TRUE and FALSE.

Refactoring: Use true intead of TRUE when calling compare_node().
It accepts a bool, not a BOOLEAN.

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().