fix info file in case if TNS_ADMIN is not set
major overhaul of locking mechanism (will work across RAC nodes)

List of changes:
1. check for number of parallel scripts running is based on .lock files
2. added RAC-awareness in terms of .lock files can be checked across
cluster (assuming .lock is in a shared fs)
3. major overhaul of renice_rman function - it now checks multiple times
until all RMAN channels start up
4. added reporting if BCT and Flashback Database are enabled