Allow tftp server to be launch in standalone mode

Add startup_mode parameter. This one take 'xinetd' or 'standalone' as
value. Default are xinetd.
Add file_init_template parameter. Permit to specify template used for
init config file.
Add default template init config file for debian.
Lint
FIX options, monitor and add test

* Fix disable and service_autorestart options.
* Should not monitor port with udp protocol
* Add some tests
Update README
Remove some trailing whitespace
Merge remote-tracking branch 'lermit/master'
Add missing parameters to fix missing vars used in the module
Actually enforce xinetd configuration when xinetd runmode is requested
Update template syntax for 3.2
Fix wrong variable reference
Merge pull request #2 from DavidS/master

This merges lermit's work and adds a few fixes of my own