ENHANCEMENT: vm models defined in extension configuration 'vm' are now virtualization provider agnostic.
BUG: NodeRelatedException is no more loosing exception's cause.
FEATURE: create custom xpath function 'GetInstanceKeyPairPassphrase'.
TYPO: enhance error messages.
ENHANCEMENT: keep the exception cause.
TEST: using lvm backed templates + UC_0 uses an encrypted key + declare all libvirt tasks.
ENHANCEMENT: upgrade bouncycastle from 1.47 to 1.50.