[WIP] Implement simple subroutine opcodes

Author: Peppece

eth/vm/rstack.py

@@ -18,7 +18,9 @@
 
 
 """
-This module simply implements for the return stack the exact same design used for the data stack. As this stack must simply push_int or pop1_int any time a subroutine is accessed or left, only those two functions are provided. For the same reason, the class RStack doesn't inherit from the abc StackAPI, as it would require to implement all the abstract methods defined.
+This module simply implements for the return stack the exact same design used for the data stack.
+As this stack must simply push_int or pop1_int any time a subroutine is accessed or left, only those two functions are provided.
+For the same reason, the class RStack doesn't inherit from the abc StackAPI, as it would require to implement all the abstract methods defined.
 """
 
 class RStack():