WORK + SAVES ROOT PASSWORD TO DISK!

The secure installation scripts connect to the
server by storing the password in a temporary
option file. Now, if the script gets killed or
fails for some reason, the removal of the option
file may not take place.

This patch introduces following enhancements :
* (.sh) Made sure that cleanup happens at every
  call to 'exit 1'. This is performed implicitly
  by END{} in pl.in.
* (.pl.in) Added a warning in case unlink fails
  to delete the option/query files.
* (.sh/.pl.in) Added more signals to the signal
  handler list. SIG# 1, 3, 6, 15