build/release: unify OSv version string for builds and releases

Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
ec2: release script for Amazon EC2 service

The script supports 3 modes of operation:
  - public release (default) for official releases
  - private release - for internal testing
  - development instance - for development

Public release means AMI created public (visible to everyone) and replicated
over all existing Amazon regions.

Private release means AMI created private (visible to releaser's account only) and
not replicated over regions.

Development instance means no AMI created, script stops after instance creation.

The script's help screen (--help command line parameter) provides detailed information
about script interface, dependencies and configurations required.

It's interesting to note that each public release made by this script costs about 20 USD
mainly because of AMI replication over Amazon regions

Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>