JCLOUDS-415 update: master now on Guava 16.0

[Andrew Phillips]

Quick heads-up that master is now on Guava 16.0. Tests looked good but  
of course please let me know if this causes any problems.

The required code changes [1] have been backported to 1.7.x, but  
that's still on Guava 15.0. Still, you should be able to use 1.7.x  
snapshots with Guava 16.0 if desired.

ap

[1]  
https://git-wip-us.apache.org/repos/asf?p=jclouds.git;a=commit;h=dc7bad39ccfd766129ee8710911420fca2e435d3