Introduce singleton types

Just for future, as this gives us a way to know immediately in the type, which represent normal, and which singleton classes
Also instantiate singleton class lazily (with singleton type)
This makes the type of class single, ie unique, immediately when it is used, ie methods or variables defined.
Fixes a design mistake, where all singletonn classes shared the same type, and thus unique methods per class were impossible
(Also some misc in commit)

lib/vool/class_method_expression.rb

@@ -41,7 +41,7 @@ module Vool
 
     def to_s(depth = 0)
       arg_str = @args.collect{|a| a.to_s}.join(', ')
-      at_depth(depth , "def self.#{name}(#{arg_str})\n#{@body.to_s(depth + 1)}end")
+      at_depth(depth , "def self.#{name}(#{arg_str})\n#{@body.to_s(1)}\nend")
     end
 
     private

lib/vool/method_expression.rb

@@ -50,7 +50,7 @@ module Vool
 
     def to_s(depth = 0)
       arg_str = @args.collect{|a| a.to_s}.join(', ')
-      at_depth(depth , "def #{name}(#{arg_str})\n#{@body.to_s(depth + 1)}\nend")
+      at_depth(depth , "def #{name}(#{arg_str})\n#{@body.to_s(1)}\nend")
     end
 
     private

lib/vool/statements.rb

@@ -72,11 +72,7 @@ module Vool
       first = stats.shift.to_mom(compiler)
       while( nekst = stats.shift )
         next_mom = nekst.to_mom(compiler)
-        if next_mom.is_a?(Mom::BlockCompiler)
-          compiler.block_compilers << next_mom
-        else
-          first.append next_mom
-        end
+        first.append next_mom
       end
       first
     end