Replace the webview with a native listview

[pyricau]

We started with a webview to allow fast iteration and integration of new features.

However :

• the webview hasn't evolved in months
• it loads way too much resources (structured html, candidate photos that are already available on the phone)
• it doesn't look good (especially the titles) and well integrated with the application style
• event handling (clicks) works randomly

So we should switch to a native listview.

Webviews on Android are crap. End of story.