Check for latest Tor Browser user agent.

The latest version of the Tor Browser has a new user agent string,
check for it in is_likely_tor_browser().
Remove DOM storage check from is_likely_tor_browser.

Remove check for disabled DOM storage as it is now enabled
for certain domains in the latest Tor Browser Bundle.
indexOf returns -1 if value not found
Merge pull request #1 from arlolra/useragent

indexOf returns -1 if value not found
Formatting.
ChangeLog for #8434.
Merge branch 'url_reg'
Use similar variable names as in flashproxy-reg-email.
Nicer URL building.
Formatting.
Show an error if the remote IP address is not given.

Unlike the http and email methods, this rendezvous method cannot guess
your external address.
ChangeLog for #7559.
ChangeLog typo.
Remove unused import.
Make URL-based registration work with HEAD as well as GET.
Disable the start function too when disabling.

Otherwise the debug mode would print the message
	Starting; will contact facilitator in 60 seconds.
even though that was false.
Add man page for flashproxy-reg-url.
Add flashproxy-reg-url manpage to Makefile.