Export and use aidset, set USE_TYPED_DSET

I did ai so I can use it as an example in the Release Notes.

modules/database/src/std/dev/devAiSoftCallback.c

@@ -153,8 +153,10 @@ static long init(int pass)
     return 0;
 }
 
-static long init_record(aiRecord *prec)
+static long init_record(dbCommon *pcommon)
 {
+    aiRecord *prec = (aiRecord *)pcommon;
+
     if (recGblInitConstantLink(&prec->inp, DBF_DOUBLE, &prec->val))
         prec->udf = FALSE;
 
@@ -213,14 +215,8 @@ static long read_ai(aiRecord *prec)
     return 2;
 }
 
-/* Create the dset for devAiSoftCallback */
-struct {
-    dset common;
-    DEVSUPFUN read_ai;
-    DEVSUPFUN special_linconv;
-} devAiSoftCallback = {
+aidset devAiSoftCallback = {
     {6, NULL, init, init_record, NULL},
-    read_ai,
-    NULL
+    read_ai, NULL
 };
 epicsExportAddress(dset, devAiSoftCallback);