[JCLOUDS-439] Fix osgi metadata on jclouds-sts.
Store propagatable exceptions in a static field

Also include ResourceAlreadyExistsException.  References JCLOUDS-438.
JCLOUDS-440: Upgrading Bouncy Castle to 1.49 (1.50 has issues with OSGi)

Artifact ID has also changed: bcprov-jdk16 -> bcprov-ext-jdk15on