Change Mom to SlotMachine

rather large commit, but essentially a simple rename
Rationale in docs and blogs

lib/risc/method_compiler.rb

@@ -7,8 +7,8 @@ module Risc
 
     # Methods starts with a Label, both in risc and mom.
     # Pass in the callable(method) and the mom label that the method starts with
-    def initialize( method , mom_label)
-      super(method , mom_label)
+    def initialize( method , slot_label)
+      super(method , slot_label)
     end
 
     def source_name