Added developer FAQ

notes/FAQ-dev.md

@@ -0,0 +1,11 @@
+Development FAQ
+===============
+
+*   **Q:** Why conditions are parsed and instantiated on slave gerneration
+    (read "so late")?
+
+    **A:** Because they are huge and there can be lots of them.  (I just could
+    not stand looking at the dump with all those same op handlers everywhere.)
+
+    However, I agree this is not nice.
+