To allow more flexibility when raising exception, add an error handler
in rdw_app to convert any known exception into the proper HTTP error
code (default to 500).

Add a new "lang" attribute and variable
Add jquery validation to javascript minify
Add jquery validation translation files and properly load them in html
Add javascript to run validation on any form[data-validation]

To avoid listing all history, limit it to 20 and allow users to show
more.

Add the path when raising exceptions.

To return the right HTTP error code, declare new assert function.

To simplify the code use a page handler to serve favicon.

Replace some misuse of ValueError by Warning()

To simplify the error handling, replace call to error.html template by a
HTTPError with the right error code.

Make the integration test (java/web tests) working in python2.

Make testcases run in py2 and py3

Ran `futurize --write --nobackups --stage1 --unicode-literals`

Split database and password validation.
Allow support for multiple password backend.

Prefix path matching was broken: `/blah` would conflict with `/blahblub`

Refactor the preferences page to use plugins architecture.

plugins: LDAP and SQLite. MySQL is on the way.

accepted language.

To benefit from cherrypy encoding,decoding,gzip filters. We need to make
the login page a page controller. This also fixes encoding issue if the
login page contains any non-ascii character.