Change Mom to SlotMachine

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

lib/slot_machine/macro/init.rb

@@ -0,0 +1,43 @@
+module Mom
+  # Init "method" is the first thing that happens in the machine
+  # There is an inital jump to it, but that's it, no setup, no nothing
+  #
+  # The method is in quotes, because it is not really a method, it does not return!!
+  # This is common to all double underscore "methods", but __init also does not
+  # rely on the message. In fact it's job is to set up the first message
+  # and to call the main (possibly later _init_ , single undescrore)
+  #
+  class Init < Macro
+    def to_risc(compiler)
+      builder = compiler.builder(compiler.source)
+      main = Parfait.object_space.get_method!(:Space, :main)
+      # Set up the first message, but advance one, so main has somewhere to return to
+      builder.build do
+        factory! << Parfait.object_space.get_factory_for(:Message)
+        message << factory[:next_object]
+        next_message! << message[:next_message]
+        factory[:next_object] << next_message
+      end
+      builder.reset_names
+      # Set up the call to main, with space as receiver
+      Mom::MessageSetup.new(main).build_with( builder )
+      builder.build do
+        message << message[:next_message]
+        space? << Parfait.object_space
+        message[:receiver] << space
+      end
+      # set up return address and jump to main
+      exit_label = Risc.label(compiler.source , "#{compiler.receiver_type.object_class.name}.#{compiler.source.name}" )
+      ret_tmp = compiler.use_reg(:Label).set_builder(builder)
+      builder.build do
+        ret_tmp << exit_label
+        message[:return_address] << ret_tmp
+        add_code Risc.function_call( "__init__ issue call" ,  main)
+        add_code exit_label
+      end
+      compiler.reset_regs
+      Macro.exit_sequence(builder)  # exit will use mains return_value as exit_code
+      return compiler
+    end
+  end
+end