Use update-rc.d to set runlevels

update-rc.d handles symlink creation more elegantly than manually
creating symlinks on Debian-based systems.

The previous manual rc2.d symlink creation would properly start the
service, but it never created the appropriate K (kill) symlinks in the
lower runlevels. As a result, the service would never actually be
stopped when the system was shutting down.
More robust init script

Init script renamed from pyto to pytomation.init

Add python shebang to main pytomation init script to allow for direct
execution without the pytomation.sh shell script.

Moved PID file creation and handling into start-stop-daemon arguments
in init script

Eliminated intermediate pytomation.sh file now that init script
starts the Pytomation python script directly

Use LSB functions for reporting init script output

Added status option to init script

Added proper Required-Start and Required-Stop entries

Updated install.sh to find and remove old init script
Update README.md

Uses Debian packages where available. pyephem is the only remaining non-Debian packaged dependency.

Clarified instructions in a few places.
Merge pull request #21 from tomstokes/master

init script and documentation clean up