Remove docs for uri-as-argument
Document that --uri is now required for URI loads
Cast the return value
Clean up uzbl.1
Merge remote-tracking branch 'gh/nmeum/next' into mathstuf/next

* gh/nmeum/next:
  Fixed installation of bin/uzbl-browser
  Fix test statement in uzbl-browser startup script
Fix the sandbox so it works again

PREFIX wasn't set, 'which' wasn't using the env.sh environment, and
more.
Don't quote the path; spaces are literal in set
Initialize the plugin instances earlier

The quit method uses it and may be called before any are loaded.
Fix downloads in WebKit1

WebKit1 downloads are synchronous, so we must run the download_handler
directly.
Typos.
Update example config for menu command changes
Minor cleanups in download.sh
Free menu items
Fix quoting in formfiller.sh
Handle comments in the core function

This allows comments and empty lines to be ignored in:

    uzbl-core -c - < file
Notify global plugins of new uzbl instances
Fix global plugin notifications
Fix some minor whitespace nits
Add support for TLS error handling
Improve docs for synchronous handlers