api: remove PaymentProviderAccount

We don't need it anymore.

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
api: limit the dependencies

We can do better, but it's a good start.

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
util: make Felix export javax.servlet and javax.servlet.api

They are not exported by default (since each bundle could use a
different version).

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
osgi: switch to whiteboard pattern to register HttpServlets

Bundles now register their servlets as services. The Killbill system bundle will
discover them and perform the registration.

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
bin: update start-server to use the logback.xml file

We did switch from log4j a while back.

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
osgi: improve robustness on startup

If a bundle fails to start, carry on.

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>