Nicer formatting for exported supervisord files

1. Remove newline from beginning of supervisord files
2. Put blank lines between [program] sections for readability

##### Example:

```ini
[program:app-alpha-1]
command=./alpha
autostart=true
autorestart=true
stopsignal=QUIT
stdout_logfile=/var/log/app/alpha-1.log
stderr_logfile=/var/log/app/alpha-1.error.log
user=app
directory=/tmp/app
environment=PORT="5000"

[program:app-alpha-2]
command=./alpha
autostart=true
autorestart=true
stopsignal=QUIT
stdout_logfile=/var/log/app/alpha-2.log
stderr_logfile=/var/log/app/alpha-2.error.log
user=app
directory=/tmp/app
environment=PORT="5001"

[group:app]
programs=app-alpha-1,app-alpha-2
```

##### Tests:

```
$ bundle exec rake spec
/Users/marca/.rvm/rubies/ruby-2.1.2/bin/ruby -S rspec spec/foreman/cli_spec.rb spec/foreman/engine_spec.rb spec/foreman/export/base_spec.rb spec/foreman/export/bluepill_spec.rb spec/foreman/export/daemon_spec.rb spec/foreman/export/inittab_spec.rb spec/foreman/export/launchd_spec.rb spec/foreman/export/runit_spec.rb spec/foreman/export/supervisord_spec.rb spec/foreman/export/systemd_spec.rb spec/foreman/export/upstart_spec.rb spec/foreman/export_spec.rb spec/foreman/helpers_spec.rb spec/foreman/process_spec.rb spec/foreman/procfile_spec.rb spec/foreman_spec.rb spec/helper_spec.rb
I, [2014-11-27T08:12:18.789614 #50079]  INFO -- : Not reporting to Code Climate because ENV['CODECLIMATE_REPO_TOKEN'] is not set.
..................................................................................

Finished in 4.68 seconds
82 examples, 0 failures

Randomized with seed 15318

Coverage report generated for RSpec to /Users/marca/dev/git-repos/foreman/coverage. 579 / 670 LOC (86.42%) covered.
```