Upgrade to netconf4j 0.0.8-SNAPHOT.
Upgrade guava to version 12.0.

This change is motivated by a uses constraint violation error.

The error is caused by having two different versions of guava libraries
(one comming from netconf4j and the other one from opennaas) used in same bundle.

This patch solves this error by unifying the version of guava being used in opennaas, that is now set to 12.0.

Oficial Guava is already published as an OSGi bundle since version 12.0. Hence, guava-osgi repackaging is no longer used.
Upgrade Guava dependency to latest release (16.0.1)
Upgrade to netconf4j 0.0.8
Merge pull request #871 from isartcanyameres/upgrade/netconf4j-0.0.8

Upgrade/netconf4j 0.0.8