Refactoring code and fixed navigation method on the manifest

[vincenzopalazzo]

This PR is the same as #55 but with some code removed, such as:

• Fixed of #54.
• Notification Startup node, at the moment we don't need it.

I hope I have fixed all your suggestions @lvaccaro.

[vincenzopalazzo]

I will work to fix the conflicts inside the class SettingsActivity this weekend

[vincenzopalazzo]

closed by #76