feat(docs): Add retesteth block options

Replacing #1116 where git got ... strange

docs/retesteth-ref.rst

@@ -103,9 +103,9 @@ Option                        Meaning
 -\\-exectimelog               Output execution time for each test suite
 -\\-stderr                    Redirect ipc client stderr to stdout
 -\\-travisout                 Output \`.\` to stdout
+-\\-statediff                 State changes between before and after the test
 ============================= ===================================================
 
-
 .. note::
 
    Normally the **-\\-vmtraceraw** output goes to standard output. However, you could specify a directory
@@ -116,6 +116,34 @@ Option                        Meaning
 
 
 
+Blockchain test debugging
+..........................
+
+Blockchain tests contain multiple transactions, so to debug them it is useful to
+look between transactions.
+
+============================== ===================================================
+Option                         Meaning
+============================== ===================================================
+-\\-statediff <a>to<c>         State changes from just after block a to 
+                               just after block c. The first block is numbered 1
+-\\-statediff <a>:<b>to<c>:<d> State changes from just after tx b on block a to
+                               just before tx d on block c. The first transaction
+                               in a block is numbered zero.
+-\\-poststate <a>              The state changes just after block a
+-\\-poststate <a>:<b>          The state just after tx b on block a
+-\\-vmtrace[raw] <a>:<b>       Trace a specific transaction          
+============================== ===================================================
+
+.. note::
+
+   You can only view the state in the middle of a block (**-\\-statediff**
+   **-\\-poststate** when you use 
+   **-\\-filltests**. Otherwise only the state at the end of blocks is 
+   available. 
+
+
+
 Additional Tests
 ----------------------------------