Introducing WiFi only uploading.

Those changes should introduce a WiFi only upload feature. My only concern is the size of ```mReports``` getting too large. It's possible that an extreme value (```mReports.length```>?) might cause some buggy behavior down the line.

I'm pretty sure I messed up something with github again. Some of the changes are already incorporated into mozilla:master (related to the on/off button), but as they are by now part of the same commit, I am not sure how to separate them (/ revert them).