Improve code style and add javadoc.

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Use the converter engine in the form mapper.

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
adding JavaDoc to the cookie helper

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Avoid catching throwable (exception is better in these cases)

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>