avr: improved timer module.

- simplified timer handling. still using cascading counters but in an
  extendable way
- added onEvery5m while on it
- renamed everyMinute to every1m (unifies routine names)
- send network stats every 5m, not every minute

avr/att84_base.asm

@@ -279,7 +279,15 @@ onEvery30s:
 ; ---------------------------------------------------------------------------
 ; Called every minute. Add your routine calls here. No arguments, no results.
 
-onEveryMinute:
+onEvery1m:
+  ret
+
+
+
+; ---------------------------------------------------------------------------
+; Called every 5 minutes. Add your routine calls here. No arguments, no results.
+
+onEvery5m:
   ret