RAC-aware and DG health checks

1. Complete overhaul in function that controls backups concurrency - now it is based on lock files and if lock
2. RAC-awareness
3. DG health checks - separate for primary and secondary databases. Primary will run backups on Primary if Standby is stale (even if asked to run backups only on Standby so we don't have stale backups)
4. Many other smaller changes

Release 1.1

1. Scripts renamed so main script and sub-scripts all end with .ksh
2. Several minor bug fixes

First release

With latest changes and being tested for quite some time, it is safe to assume this version should be a 1.0 release.

First pre-release

It is production ready,but I would give it more time to test and may implement a few improvements here and there