Update: memory changes, macro changes, and return type changes.

Update: memory changes, macro changes, and return type changes.

The practice of having an increase(), increase_by(), etc.. has become standard.
Redesign the code to better follow this, simplifying the code base some.
There is more work to do in this regard, but this focuses on just changing the existing code.

While I prefer to always return "const" where I can, simplify the design to always return "f_status_t" instead of using the wrapping macro "f_return_status".
This will make things between C and C++ more consistent.