osmo: Make it possible to register on the OsmoAppConnection IPADispatcher

OsmoAppConnection now can call a block registered with >>#onConnect:
to allow modifying the dispatcher. This can be used to register for
the SCCP protocol. Use >>#nextPut:with: to send information through
the muxer.

osmo/OsmoAppConnection.st

@@ -17,7 +17,8 @@
 "
 
 Object subclass: OsmoAppConnection [
-    | socket writeQueue demuxer muxer dispatcher token hostname port tx_proc rx_proc started |
+    | socket writeQueue demuxer muxer dispatcher token hostname port
+        tx_proc rx_proc started connect_block |
     <category: 'OsmoNetwork-Socket'>
     <comment: 'I connect to a OpenBSC App on the Control Port and wait for
 TRAPS coming from the server and will act on these.
@@ -83,6 +84,11 @@ TODO: re-use the IPADispatcher across connections.'>
 
     initializeDispatcher [
         "Allow another class to register handlers"
+        connect_block ifNotNil: [connect_block value: dispatcher].
+    ]
+
+    nextPut: aData [
+        muxer nextPut: aData with: IPAConstants protocolOsmoCTRL
     ]
 
     token: aToken [
@@ -99,6 +105,13 @@ TODO: re-use the IPADispatcher across connections.'>
         port := aPort
     ]
 
+    onConnect: aBlock [
+        <category: 'creation'>
+        "Call the block when the socket is being connected and the dispatcher
+        is set-up. The callback will have the dispatcher as parameter."
+        connect_block := aBlock.
+    ]
+
     createConnection: aHostname port: aPort [
         <category: 'socket'>
         ^ Sockets.Socket remote: aHostname port: aPort.

osmo/OsmoCtrlConnection.st

@@ -38,6 +38,6 @@ OsmoAppConnection subclass: OsmoCtrlConnection [
     ]
 
     sendCtrlData: aData [
-        muxer nextPut: aData with: IPAConstants protocolOsmoCTRL.
+        self nextPut: aData with: IPAConstants protocolOsmoCTRL
     ]
 ]