Make the code somewhat smaller. Disable disk failure test for master for now.

Reviewed-by: schreiberal

- Split main() function into several small ones.
- Current work on disk failure tests. This is not yet finished.
- Fix small typo in qa_node.py.

Reviewed-by: schreiberal

Testing failure on the primary node is currently disabled due to drbd problems.

Reviewed-by: iustinp

Reviewed-by: iustinp

Reviewed-by: iustinp

Reviewed-by: iustinp

Reviewed-by: schreiberal

- Implement colours in qa_utils.
- Print warning for cron script.

Reviewed-by: iustinp

Added tests:
- “gnt-cluster getmaster”
- “gnt-cluster version”
- “gnt-instance list”
- “gnt-instance reinstall”

Reviewed-by: schreiberal

- Test “gnt-backup export” and “gnt-backup import”.
- Move “ResolveInstanceName” to qa_utils.py.
- Fix tests for “ganeti-watcher”.
- Make instance shutdown and startup configurable.

Reviewed-by: schreiberal

Reviewed-by: iustinp

Reviewed-by: iustin