DevToolsAppStartup component

Handles the -start-debugger-server command line option and will sync the
debugger server status with the remote-enabled pref.
Introducing nsIDebuggerServerController
add support for debuggercontroller to debugger server
Firefox Desktop Debugger controller
remove debugger server code from Metro frontend
strings for debugger controllers notifications
B2G Debugger controller
remove debugger server code from B2G frontend
Fennec Debugger controller
remove debugger server code from Android frontend
repurpose the meaning of the remote-enabled pref
toolboxprocess.jsm should use the controller
Are these changes needed?