Fixed memory leaks
Fixed a double free bug
Fixed a crash bug that signal callback is incorrect released
Fixed a crash bug that happened when service was registered
Fixed a bug that lacks a argument for object handler
remove unneccessary message
make it doesn't need to use process.nextTick to call method
Fixed a crash bug that unref DBusPendingCall before function call
remove unnecessary code and unref handler
bump to v0.2
Merge pull request #50 from cfsghost/development

Fixed a lot bugs