README improvements

 * Advise ``TIME_ZONE = 'UTC'`` so that times in the database don't
   require migration when moving to ``USE_TZ = True`` (otherwise you
   must dump the database, fiddle with settings.py, flush, load—praying
   that no dates fall on a DST transition—and fiddle again).
 * Fix reST syntax error.
Allow img[alt] in feed content by default
Test for img[alt] and other attributes
Remove unused symbols in tests

They were making pyflakes angry, and if XML isn't available this whole
"RSS reader" thing is kinda hopeless, right?
Fix ``YARR_LAYOUT_FIXED = False`` in JS

Was setting the data attribute instead of reading it.
Don't import the admin (why?)
Allow chronological display of feed items

Add a new button to the toolbar to switch between "Latest first" and
"Oldest first" ordering.
Merge pull request #15 from twm/readme-improvements

README improvements
Merge pull request #16 from twm/bleach-allow-img-alt

Allow <img alt> by default
Merge pull request #17 from twm/disable-fixed-layout

Fix ``YARR_LAYOUT_FIXED = False`` in JS
Merge pull request #18 from twm/chronological

Allow chronological display of feed items
Bump version to 0.3.8
0.3.9: Fixed layout fixed setting in list view