Use different value for def.domain when in sandbox

The production domain is synth.pl, lets use synth.dev for the testing
environment. Also reformat the def.cf file to match the defined style.
replace 'synth.pl' with
move hosts template to an external file
when adding CFEngine APT repo don't create backup of the empty file
don't create backup for ...apt.conf.d/20recommends file
Fix typos in package_add_command for gems
Install root: kklimonda alias inside postfix bundle

It makes no sense to handle postfix related configuration in the
global config file. Also inserting new aliases to /etc/aliases
there would require for edit_line to depend on postfix package
being installed first.
make sure that the target directory exists before unpacking
Send HUP signal to init under sandbox to reload

upstart under LXC doesn't seem to be reloading jobs properly, so send
it a HUP signal forcing it to do it.
remove gitolite bundle