Change uProxy extension and app names to 'uProxy, part 1 of 2' and 'uProxy, part 2 of 2'

Change uProxy extension and app names to 'uProxy, part 1 of 2' and 'uProxy, part 2 of 2'

Tested in Chrome
Doe we have one of these files that's ```appName``` and the other that's ```extensionName```? Down the line we'll one 1 messages.json file that we copy into both of these, so it would be good if they don't collide.