use dev for maintenance branch version

instead of 'maint'

PEP 440 made anything other than 'dev' unparseable

IPython/core/release.py

@@ -22,7 +22,7 b" name = 'ipython'"
 _version_major = 3
 _version_minor = 2
 _version_patch = 0
-_version_extra = 'maint'
+_version_extra = 'dev'
 # _version_extra = 'rc1'
 # _version_extra = ''  # Uncomment this for full releases
 

IPython/html/static/base/js/namespace.js

@@ -4,7 +4,7 b''
 var IPython = IPython || {};
 define([], function(){
     "use strict";
-    IPython.version = "3.1.0";
+    IPython.version = "3.2.0-dev";
     IPython._target = '_blank';
     return IPython;
 });