gsm: Refactor opening a transaction allowing for authentication

Make it possible to add authentication into a central place of
the MSC. Right now a prcedure will allocate the transaction and
then add it to the connection. The connection can decide when the
transaction is started.

src/GSMLURequest.st

@@ -29,8 +29,7 @@ OsmoGSM.GSM48LURequest extend [
         tran := (GSMLURequest on: aSapi with: self ti)
                   con: aCon;
                   yourself.
-        aCon addTransaction: tran.
-        tran start: self.
+        aCon openTransaction: tran with: self.
     ]
 ]
 

src/GSMMOCall.st

@@ -1,5 +1,5 @@
 "
- (C) 2011 by Holger Hans Peter Freyther
+ (C) 2011-2012 by Holger Hans Peter Freyther
  All Rights Reserved
 
  This program is free software: you can redistribute it and/or modify
@@ -65,8 +65,7 @@ OsmoGSM.GSM48CCSetup extend [
         tran := (GSMMOCall on: aSapi with: self ti)
                     con: aCon;
                     yourself.
-        aCon addTransaction: tran.
-        tran start: self.
+        aCon openTransaction: tran with: self.
     ]
 ]
 

src/GSMProcessor.st

@@ -297,6 +297,12 @@ hosting various transactions and dispatching to them.'>
         ].
     ]
 
+    openTransaction: aTran with: aMsg [
+        <category: 'transaction'>
+        self addTransaction: aTran.
+        aTran start: aMsg.
+    ]
+
     addTransaction: aTran [
         <category: 'private'>
         "Must be locked"