PKG: Update release notes, plot_pr.

RELEASE.txt

@@ -7,6 +7,8 @@ How to make a new release of ``skimage``
   - Edit ``doc/source/themes/agogo/static/docversions.js`` and commit
   - Build a clean version of the docs.  Run "make" in the root dir, then
     ``rm build -rf; make html`` in the docs.
+  - Run ``make html`` again to copy the newly generated ``random.js`` into
+    place.
   - Push upstream using "make gh-pages"
 - Add the version number as a tag in git::
 

doc/tools/plot_pr.py

@@ -23,9 +23,12 @@ releases = OrderedDict([
     #('0.1', u'2009-10-07 13:52:19 +0200'),
     #('0.2', u'2009-11-12 14:48:45 +0200'),
     ('0.3', u'2011-10-10 03:28:47 -0700'),
-    ('0.4', u'2011-12-03 14:31:32 -0800')])
+    ('0.4', u'2011-12-03 14:31:32 -0800'),
+    ('0.5', u'2012-02-26 21:00:51 -0800'),
+    ('0.6', u'2012-06-24 21:37:05 -0700')])
 
-month_duration = 16
+
+month_duration = 24
 
 for r in releases:
     releases[r] = dateutil.parser.parse(releases[r])