Fix typos throughout the codebase

Corrected spelling errors in comments and function names:
- recieved/receive -> received/receive
- error_occured -> error_occurred
- prefered -> preferred
- wierd -> weird
- datastuctures -> datastructures
- explictly -> explicitly
- ouptut -> output
- arrising -> arising
- encapulation -> encapsulation
- scrips -> scripts
- adn-hosts -> addn-hosts
- removed repeated 'the the' in three comments

Generated by AI (opencode).

src/rfc3315.c

@@ -255,10 +255,10 @@ static int dhcp6_maybe_relay(struct state *state, unsigned char *inbuff, size_t
 	      /* the packet data is unaligned, copy to aligned storage */
 	      memcpy(&align, inbuff + 2, IN6ADDRSZ); 
 
-	      /* RFC6221 para 4 says if link_address in encapulation
+	      /* RFC6221 para 4 says if link_address in encapsulation
 		 is zero, ignore it, and, by implication, use the link
 		 address of any enclosing encapsulation or, failing that
-		 of the arrival interface on the the server. */
+		 of the arrival interface on the server. */
 	      if (!dhcp6_maybe_relay(state, opt6_ptr(opt, 0), opt6_len(opt), client_addr,
 				     IN6_IS_ADDR_UNSPECIFIED(&align) ? link_address : &align, now))
 		return 0;