osgi: remove dependency on fileinstall bundle

OSGI bundles are now discovered as follow:

* {killbill.osgi.bundle.install.dir}/platform/ is scanned
for pure OSGI bundles (e.g. SLF4J, JRuby, ...)
* {killbill.osgi.bundle.install.dir}/plugins/java is scanned
for Killbill Java plugins
* {killbill.osgi.bundle.install.dir}/plugins/ruby is scanned
for Killbill Ruby plugins

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
Merge branch 'new-paymentpluginapi' of github.com:killbill/killbill into new-paymentpluginapi