Minor tweaks to scripts and jdbc tlog handling

1. Use templates for the pre and post hooks rather than
generating them via ruby
2. Named the scripts as preStart and postStart scripts and reference them
from release phase
3. Allow grace shutdown time interval to retreive files/data from warden
instance before it gets destroyed
4. Use only appname and instance index for renaming the server
references (dropping the space name) as this leads to very large fields
and failures with TLog storage on db side
5. Update docs on new scripts and parameters