Merge branch 'release/1.0' into develop
prepare for next development iteration.
Retrieve master instance AMI ID from parameter.

Windows AMI provided by amazon is not sustinable, because it is
unregistered when the new version is released.
So the AMI-ID of windows instance cannot be written within the template.
support spot instances for slaves.
add parameters to properties file.
Merge branch 'feature/support_spot_instances' into develop
set version label to 1.1
Merge branch 'release/1.1'