Copy configurl.txt to .lantern.

Shameless copy&pasta from what we used to do with fallback.json.
First shot at having configurl.txt copied to user folder on install.

Untested as of yet.
Read configurl.txt and store the URL in settings.
Move existing logic to a separate class.

Also proof of concept to check that downloading the config works.
Parse S3 config.
Ignore unrecognized JSON properties.

So we can add them for the benefit of newer clients.
Hook DefaultProxyHandler to DefaultS3ConfigManager.java.

So it gets the fallback proxy info from there.  Also, it should know
to refresh its fallbacks when they change (this part is untested).
Keep rescheduling config recheck; logging improvements.

At this point I have also tested that reapplying configuration works.
Add fallback certificates.
Set/refresh controller ID from S3 config.
Changed to newest instead of latest #1328
Changed to newest instead of latest #1328
Copy over configurl.txt directly from /opt/lantern-net-installer/

The file is readable by anyone, so the client can copy it without
root privileges.
Changed to use non-snapshot dependency
Try and copy the wrapper configurl.txt to the user's home folder.

Since this is run as a post-process of the main installer, it will
only work if the wrapper has unpacked its files before it runs the
main installer.  (Failing that, it may work the second time a user
tries to install. :P)
Moved configurl copying to happen before downloading the main installer
update to latest lantern-ui
Merge branch 'master' into issue1265

Conflicts:
	install/wrapper/wrapper.install4j
Move, not copy, configUrl.txt to the user's home folder.

This is not to leak the config to other users in the same machine,
since the file is readable by everyone in /opt/lantern-net-installer.
Don't copy configurl.txt from /opt/lantern-net-installer

It makes no sense now that we're moving the file on install in
Ubuntu.