Android upload (WIP)

[diegomura]

Screenshot

Todo:

• Handle page reload when return from finder
• Update state user info (for updating the header for example)
• Refactor JS classes a little bit
• Document Java code
• Test app overall features in physical device

Fixes #62

[diegomura]

@patte all native and JS code done. Hope you liked the changes!

Since this change extends native Webview's functionalities (critical component in the project), the last point I think it would be nice is to check app overall functionality in a physical device. I tested it extensively on the emulator and everything worked perfectly, but still.

[diegomura]

Going to merge this and release a new version to testing today.
I think this is something we can test on physical devices using this new test version