WIP - Implement running invoker as a daemon
Implement stop command

Stops Invoker if it is running as a daemon.
Extract daemons code to a separate class
Handle change of current directory during daemonization

Processes with relative path should work if Invoker is running as a 
daemon.
Refactor reactor to accomadate read and write
Reduce logging from DNS module
refactor constant loading
Refactor reactor to have separate reader and writer pars
Fix minor errors after upgrading invoker
Fix warning with File.exist?
Make all run_commands return true indicating socket should be closed
tailing a process working now
Start adding support for tailing multiple processes
Replace 'daemon' gem with a custom script

Taken from https://github.com/code-mancers/borg/blob/master/lib/borg/borg_daemon.rb
Include help as valid command
Refactor daemonizing code for style problems
Further refactor redirection io logic to remove duplication
Merge remote-tracking branch 'origin/refactor-reactor' into merge-reactor-branch

Conflicts:
	lib/invoker/cli.rb
	spec/invoker/commander_spec.rb
Remove constants used for the daemon option
Fix 'copy dns information' spec