* Massive reduction in heap space allocation, going from settings struct
264kb to 119Kb
* Use NAME_MAX_LENGTH for base paths/names, etc
* Use DIR_MAX_LENGTH for directory sizes
as deprecated.
* Use fill_pathname_join_special in the vast majority of cases where
we can ensure out_path is a new empty string
* Get rid of some extension concatenation with strlcat where encountered
* Some general cleanups with NULL termination of strings that get immediately
passed to strlcpy/strlcpy-adjacent functions
