NetServices: Add debugging constants and messages

These allow for additional messages about the progress/status of the request.
For now, the messages are sent unconditionally, though it may be reasonable to
in the future switch to sending them only when enabled.

Change-Id: Ic45a0055037af02c689494fa5ce0acd03592ad7e

docs/user/book.dox

@@ -678,7 +678,7 @@ snooze_until(time - Latency(), B_SYSTEM_TIMEBASE);
 			</td>
 		</tr>
 		<tr>
-			<td>\ref BPrivate::Network::UrlEvent::HttpRedirect "UrlEvent::HttpRedirect</td>
+			<td>\ref BPrivate::Network::UrlEvent::HttpRedirect "UrlEvent::HttpRedirect"</td>
 			<td>
 				The network services kit is handling a HTTP redirect. The request will be repeated
 				for a new URL.
@@ -768,7 +768,7 @@ snooze_until(time - Latency(), B_SYSTEM_TIMEBASE);
 			<td>
 				\ref BPrivate::Network::UrlEventData::Id "UrlEventData::Id" \c int32 <br/>
 				\ref BPrivate::Network::UrlEventData::DebugType "UrlEventData::DebugType"
-					\c int32 <br/>
+					\c uint32 <br/>
 				\ref BPrivate::Network::UrlEventData::DebugMessage "UrlEventData::DebugMessage"
 					\ref BString
 			</td>

docs/user/netservices/NetServicesDefs.dox

@@ -410,7 +410,10 @@ namespace Network {
 
 /*!
 	\var const char* UrlEventData::DebugType
-	\brief An \c int32 representing a debug type constant.
+	\brief An \c uint32 representing a debug type constant.
+
+	The value is one of \ref UrlEventData::DebugError, \ref UrlEventData::DebugWarning or
+	\ref UrlEventData::DebugInfo.
 
 	\since Haiku R1
 */
@@ -424,6 +427,31 @@ namespace Network {
 */
 
 
+/*!
+	\var UrlEventData::DebugInfo
+	\brief Value for \ref UrlEventData::DebugType indicating that the message is an info messsage.
+
+	\since Haiku R1
+*/
+
+
+/*!
+	\var UrlEventData::DebugWarning
+	\brief Value for \ref UrlEventData::DebugType indicating that the message is a warning
+		messsage.
+
+	\since Haiku R1
+*/
+
+
+/*!
+	\var UrlEventData::DebugError
+	\brief Value for \ref UrlEventData::DebugType indicating that the message is an error messsage.
+
+	\since Haiku R1
+*/
+
+
 } // namespace Network
 
 } // namespace BPrivate