Stellarium PC Android port

Trying to port as much as possible of Stellarium PC version to Android. See Stellarium/stellarium for credits of the original code.

Current state

Able to show main interface, display planets and satellities.

Many functionalities on main interface is working, including a bunch of plugins.

Known issues

Currently very early in progress so there are a lot of issues to work on

1. Crashes when performing certain functionalities: 1.1 Ephemiral calculation 1.2 Switching SkyCulture
2. showmysky cannot be compiled and has to be disabled
3. UI does not fit onto even modern hdpi display phones
4. No app icon, and need better AndroidManifest.xml
5. No zoom
6. No multi-language support