tidy-up: miscellaneous

- avoid "will" in builds scripts, scripts folder, curl_easy_ssls_export.md,
  and few other files.
- badwords: add "initialise", "nul terminated", "thread safety" and
  variations.
- prefer "null-terminat", where missing (two places).
- fix "null-terminat*" missing dash.
- hostip: merge two `#if` blocks.
- tool_doswin: fix comment
  Spotted by GitHub Code Quality
  Follow-up to 9a2663322c #17572
- fix stray spaces and newlines.

Closes #21638

lib/mprintf.c

@@ -423,7 +423,6 @@ static bool parse_conversion(const char f, unsigned int *flagp,
   return FALSE;
 }
 
-
 static int parsefmt(const char *format,
                     struct outsegment *out,
                     struct va_input *in,
@@ -968,7 +967,6 @@ static bool out_pointer(void *userp,
  *
  * All output is sent to the 'stream()' callback, one byte at a time.
  */
-
 static int formatf(void *userp, /* untouched by format(), sent to the
                                    stream() function in the second argument */
                    /* function pointer called for each output character */