Merge branch 'sim'

diff --cc doc/todo/git-annex_proxies.mdwn
index a3833085e74e0391e637b6f353157f22ecbb8deb,51ef17adcb9b2f1050aab5aa5cfccded7eceefa0..812bee88db1f9d4ee5a52a81fbfd5b6047644637
--- 1/doc/todo/git-annex_proxies.mdwn
--- 2/doc/todo/git-annex_proxies.mdwn
+++ b/doc/todo/git-annex_proxies.mdwn
@@@ -29,15 -29,27 +29,28 @@@ Planned schedule of work
  ## work notes
  
  * Currently working in [[todo/proving_preferred_content_behavior]]
 +  in the `sim` branch.
  
- ## items deferred until later for balanced preferred content and maxsize tracking
+ * sim: Add support for metadata, so preferred content that matches on it
+   will work
+ 
+ * The sim cannot be safely interrupted, or two processes be run
+   concurrently. Both unlike other git-annex commands. Either document these
+   limitations, or add locking and make it detect when it was interrupted
+   and re-run the sim from the start to resume.
  
- * `git-annex assist --rebalance` of `balanced=foo:2` 
-   sometimes needs several runs to stabalize.
+ ## completed items for September's work on proving behavior of preferred content
  
-   May not be a bug, needs reproducing and analysis.
-   Deferred for proving behavior of balanced preferred content stage.
+ * Static analysis to detect "not present", "not balanced", and similar
+   unstable preferred content expressions and avoid problems with them.
+ * Implemented `git-annex sim` command.
+ * Simulated a variety of repository networks, and random preferred content
+   expressions, checking that a stable state is always reached.
+ * Fix bug that prevented anything being stored in an empty
+   repository whose preferred content expression uses sizebalanced.
+   (Identified via `git-annex sim`)
+ 
+ ## items deferred until later for balanced preferred content and maxsize tracking
  
  * The assistant is using NoLiveUpdate, but it should be posssible to plumb
    a LiveUpdate through it from preferred content checking to location log