CLEANUP: assorted typo fixes in the code and comments

This is 16th iteration of typo fixes
diff --git a/src/cache.c b/src/cache.c
index f03944f..3f95195 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -1198,7 +1198,7 @@
 	 * subsequent request having the same primary key will have its accepted
 	 * encodings tested upon the cached response's one.
 	 * We will not cache a response that has an unknown encoding (not
-	 * explicitely supported in parse_encoding_value function). */
+	 * explicitly supported in parse_encoding_value function). */
 	if (cache->vary_processing_enabled && vary_signature)
 		if (set_secondary_key_encoding(htx, object->secondary_key))
 		    goto out;