is_good_baseurl(): eliminate some false positives
also fetch used images when fetching 'redirected revisions'

when fetching by revision, and the revision points to a redirected
page, we already did fetch the redirected page by title. we also need
to call fetch_used for that title.

here's an example metabook.json that revealed the bug:

,----[ metabook.json ]
| {
|     "items": [
|         {
|             "content_type": "text/x-wiki",
|             "currentVersion": 1,
|             "latest": 423796393,
|             "revision": 423796393,
|             "timestamp": "1302664603",
|             "title": "ESRI grid",
|             "type": "article",
|             "url": "http://en.wikipedia.org/wiki/ESRI_grid"
|         }
|     ],
|     "licenses": [],
|     "subtitle": "",
|     "summary": "",
|     "title": "GMS 2",
|     "type": "collection",
|     "version": 1,
|     "wikis": [
|         {
|             "baseurl": "http://en.wikipedia.org/w/",
|             "imagesize": 1200,
| 	    "script_extension": ".php",
|             "type": "wikiconf"
|         }
|     ]
| }
`----
install Pillow

Pillow is the "friendly" PIL fork by Alex Clark and Contributors. PIL
is the Python Imaging Library by Fredrik Lundh and Contributors.
do not install pil in tox testenv
update installation instructions

we don't need to manually install pil anymore.
prepare 0.15.8 release
fix imports in test_nserve.py and move it to tests directory

fix imports since nserve.py has been moved to mwlib/nserve.py. now
there's also no need to keep the test in the sandbox directory
anymore.
update MANIFEST.in
use tox 1.5's whitelist_externals in order to suppress warnings
mention that template blacklisting and print templates do not work
anymore.

see https://github.com/pediapress/mwlib/issues/32
get rid of template blacklisting/print templates in nslave and postman
remove more template blacklisting/template exclusion handling code
set timeout for makezip in postman

the default timeout used by qserve is 2 minutes, which is a bit low for
some wikis.
prepare mwlib 0.15.9
make make-manifest useable as pre-commit hook
Add --serve-files-address parameter to nslave.

Allows to specify listen address to bind nslave to a specific
interface/address. Defaults to '0.0.0.0' to keep default behaviour.
merge pull request 31/is_good_baseurl fixes
only log error if it's not ENOENT in purge_cache

we now also only catch OSErrors...

I'm tired of getting mails from the cron job...
catch errors while examining directory in purge_cache
don't step into nested directories in purge_cache