misc: Ease porting and use "self basicNew initialize" for init

self basicNew initialize will work on Pharo and various versions
of GST and will make sure to call initialize exactly once.

SCCPHandler.st

@@ -39,7 +39,7 @@ Object subclass: SCCPConnectionState [
 
     SCCPConnectionState class >> on: aHandler [
         <category: 'creation'>
-        ^ super new
+        ^(self basicNew)
             initialize;
             conManager: aHandler;
             yourself
@@ -463,7 +463,7 @@ deadlocks should not occur.'>
 
     SCCPHandler class >> new [
         <category: 'creation'>
-        ^ super new initialize; yourself
+        ^self basicNew initialize
     ]
 
     initialize [