include: Improved SDL_GetTicks*() documentation a little.

include/SDL_timer.h

@@ -42,9 +42,11 @@ extern "C" {
  *
  * This value wraps if the program runs for more than ~49 days.
  *
- * \deprecated This function is deprecated as of SDL 2.0.18; use
- *             SDL_GetTicks64() instead, where the value doesn't wrap
- *             every ~49 days.
+ * This function is not recommended as of SDL 2.0.18; use SDL_GetTicks64()
+ * instead, where the value doesn't wrap every ~49 days. There are places in
+ * SDL where we provide a 32-bit timestamp that can not change without
+ * breaking binary compatibility, though, so this function isn't officially
+ * deprecated.
  *
  * \returns an unsigned 32-bit value representing the number of milliseconds
  *          since the SDL library initialized.
@@ -53,15 +55,15 @@ extern "C" {
  *
  * \sa SDL_TICKS_PASSED
  */
-extern SDL_DEPRECATED DECLSPEC Uint32 SDLCALL SDL_GetTicks(void);
+extern DECLSPEC Uint32 SDLCALL SDL_GetTicks(void);
 
 /**
  * Get the number of milliseconds since SDL library initialization.
  *
  * Note that you should not use the SDL_TICKS_PASSED macro with values
  * returned by this function, as that macro does clever math to compensate
- * for the 32-bit overflow every ~49 days. 64-bit values can just be safely
- * compared directly.
+ * for the 32-bit overflow every ~49 days that SDL_GetTicks() suffers from.
+ * 64-bit values from this function can be safely compared directly.
  *
  * For example, if you want to wait 100 ms, you could do this:
  *
@@ -85,7 +87,8 @@ extern DECLSPEC Uint64 SDLCALL SDL_GetTicks64(void);
  * days, but should _not_ be used with SDL_GetTicks64(), which does not have
  * that problem.
  *
- * For example, if you want to wait 100 ms, you could do this:
+ * For example, with SDL_GetTicks(), if you want to wait 100 ms, you could
+ * do this:
  *
  * ```c
  * const Uint32 timeout = SDL_GetTicks() + 100;