Update: wrap some macros in functions and minor cleanups.

Update: wrap some macros in functions and minor cleanups.

The macro design has its uses but to save compiled size provide functions that are essentially wrappers to the macros.
Macros can also be flakey and sensitive while being harder to debug.
The delete functions that wrap the macros use the delete_simple macro.

Make the fss_macro.h and its contents private.

When decreasing, instead of using "if (X - 1 > 0)..." use "if (X > 1)...".
This avoids performing a math operation when it could otherwise be avoided.