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

docs/FAQ.md

@@ -986,7 +986,7 @@ programs. libcurl uses thread-safe functions instead of non-safe ones if your
 system has such. Note that you must never share the same handle in multiple
 threads.
 
-There may be some exceptions to thread safety depending on how libcurl was
+There may be some exceptions to thread-safety depending on how libcurl was
 built. Please review [the guidelines for thread
 safety](https://curl.se/libcurl/c/threadsafe.html) to learn more.
 

docs/THANKS-filter

@@ -25,7 +25,7 @@
 # This is a list of names we have recorded that already are thanked
 # appropriately in THANKS. This list contains variations of their names and
 # their "canonical" name. This file is used for scripting purposes to avoid
-# duplicate entries and will not be included in release tarballs.
+# duplicate entries and is not included in release tarballs.
 # When removing dupes that are not identical names from THANKS, add a line
 # here!
 #

docs/libcurl/curl_easy_ssls_export.md

@@ -149,8 +149,7 @@ int main(void)
   if(curl) {
     curl_easy_setopt(curl, CURLOPT_SHARE, share);
 
-    /* run a transfer, all TLS sessions received will be added
-     * to the share. */
+    /* run a transfer, all TLS sessions received are added to the share. */
     curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
     curl_easy_perform(curl);
 

docs/libcurl/libcurl-thread.md

@@ -13,12 +13,12 @@ Added-in: n/a
 
 # NAME
 
-libcurl-thread - libcurl thread safety
+libcurl-thread - libcurl thread-safety
 
 # Multi-threading with libcurl
 
 libcurl is thread-safe but has no internal thread synchronization. You may have
-to provide your own locking should you meet any of the thread safety exceptions
+to provide your own locking should you meet any of the thread-safety exceptions
 below.
 
 # Handles

docs/libcurl/libcurl.md

@@ -174,7 +174,7 @@ to select the active SSL backend.
 
 The global constant functions are thread-safe since libcurl 7.84.0 if
 curl_version_info(3) has the CURL_VERSION_THREADSAFE feature bit set
-(most platforms). Read libcurl-thread(3) for thread safety guidelines.
+(most platforms). Read libcurl-thread(3) for thread-safety guidelines.
 
 If the global constant functions are *not thread-safe*, then you must
 not call them when any other thread in the program is running. It