Always encapsulate command arguments in quotes

MPD accepts both quoted and unquoted command arguments but drop in replacements like Mopdiy might require quoted arguments so safer to just escape.
Fixed connection and authentication issue

StandAloneMonitor would cause exception because MPD was not set in commandExecutor. setMpd() called on commandExecutor before instantiating standAloneMonitor.
setMpd() was called twice, both in bind and in the constructor, removed constructor one
authenticate was not called before StandAloneMonitor would do status poll. Rearanged initalization so no authentication errors occur on startup.
Removed initual output loading from constructor

admin field is not injected untill after constructor call so it will have to wait for the first check.
Merge pull request #25 from sleepkever/develop

Always encapsulate command arguments in quotes