Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Mon, 14 Oct 2013 18:59:12 +0200] rev 19904
shelve: drop pickle usage
Pickle was used to the `shelvedstate` file. However the content of the file is
very simple and we can handle serialisation ourself. Not using pickle is a net
win.
Note incrementing the format version as no releases have been done so far.