Just a weird, meaningless footgun waiting in the wings for someone to catch themselves on. D_StartTitle works plenty fine here!

D_PostEvent_end is only used by Allegro (used by the DOS port) to help timers work, so check for PC_DOS in preprocessor code. Also remove FUNCMATH from said function.

Also corrected what appears to be a typo in some comments above?

Fix all compilation errors (tested using DEBUGMODE=1 and ERRORMODE=1) that remain outstanding. Notably:
	* Remove FUNCMATH from all void-returning functions, given GCC80 specifically complains about this case.
	* Extend the length of all extant buffers to the safety threshold recommended by the compiler.
	* Add void casts to WS_getaddrinfo's setting to prevent complaints about incompatible typecasts.
	* Extend the charsel, face, and superface buffer sizes and writes to include the null terminator. (I didn't really want to do this because it's not even particularily NEEDED, but there was literally zero way to get around the request that I could find with multiple online searches. I tried.)

(no actual SLOC changes)