hook Config GUI to trigger on LinJam::IsAudioEnabled value holder (issue #12)

* added LinJam::HandleTimer() method
* removed LinJam::HandleChatCommand() method
* removed LinJam::IsInitialized class var
* changed LinJam::IsAudioEnabled to value holder for Config GUI
* added LinJam::ConfigDismissed() method
* added NJC_STATUS_AUDIOERROR to NJClient::ConnectionStatus enum
* removed LinJamApplication::getContainerComponent() , getChildComponent() methods
* renamed ConfigClient class to Config
* renamed ConfigNinjam class to ConfigClient
* removed GUI::UNKNOWN_STATUS_TEXT
* moved configButton from MasterChannels to MainContent
* added GUI::CONFIG_BTN_X , CONFIG_BTN_Y constants
* renamed GUI::CONFIG_BTN_XC , CONFIG_BTN_YC constants to
          GUI::HOVER_BTN_XC  , HOVER_BTN_YC
* removed juce audio modules
* removed juce audio device types constants