Release version 0.62 (webpy#692)

Fix incorrect MANIFEST.in. (webpy#663)

Updated the latest version in README.

Update setup.py.

Bump version number: 0.50.

Fixed the issue of len not working with the result of db query. (webp…

…y#554)

* Fixed the issue of len not working with the result of db query.

The earlier implentation was adding an __len__ function to the result
object and that worked fine for old-style classes. With old-style
classes gone in Python 3, that started giving trouble. Fixed it by
writing a ResultSet class and a special SqliteResultSet which doesn't
support len, but supports bool.

Fixes webpy#547.

* cleanup of db tests.

switched to setuptools

Bumped version to 0.38 and updated ChangeLog

Added ChangeLog.

web.py 0.36 released.