fix #595: If expressions broken in STPL after upgrading

Fixed an error where everything before a block keyword (if/for/...) was
removed by the template parser. Example::

    % m = 'a' if True else 'b'

was translated to::

    if True else 'b'

insead of::

    m = 'a' if True else 'b'
Set new pypi to MongoDB Bottle Plugin
Merge pull request #596 from avelino/docs-mongo-plugin

Set new pypi to MongoDB Bottle Plugin
Updated error page template

I removed some unused imports and changed "font-family: sans" to "font-family: sans-serif", which I assume it was meant to be.
Merge pull request #597 from a-e-m/master

Updated error page template
Fix sample websocket via gevent-websocket
update api: https://pypi.python.org/pypi/gevent-websocket/
Merge pull request #598 from avelino/doc-async-websocket-sample

Fix sample websocket via gevent-websocket