- added gradle build file for the 'UsbSerialLibrary' android library.
- updated gradle build file for the 'Android' project to include dependency for the 'UsbSerialLibrary' project.
- removed MapManager, and MissionItemDetailManager.
completed base implementation of MissionRender.
- added a mission render singleton for the whole application.
- finalized drone instance fields.
completed integration of the new Android mission, and mission items structure.
started to add back missing functionality.