Merge pull request #103 from cvogeley/master

More mobile stuff
basic structure for premium channel implementation
Merge https://github.com/friendica/red into zpull
implement premium channel discovery
progress on generic sellpage - is not yet linked from existing connect buttons and editing has not been completed
premium/restricted channel connections implemented, configure at yoursite/channel/nickname - this basically redirects "follow" requests to a premium channel's sell page if it has one configured. You can still click through and create a connection request (introduction), but this provides a means for the channel owner to state their terms. If you don't abide by the terms, you will likely be blocked or the channel deleted. This facility is extensible in a number of ways.
fixes for sellpage with blocked profiles
add zid to connect_url
make premium channels a feature
add detailed logging to public recips - find out why some public recipients are getting bypassed (David Benfells' problem with tagging groups, etc.)
possible fix for mention tags not posting to mentioned forum (when send stream permission is blocked)
extra logging for translating likes in notification emails - which is still failing on occasion.
perform a refresh_all operation after changing premium status so that everybody will catch it quickly and not in a day or two.
proc_run, not proc_exec
this should fix the premium checkbox stickiness issue
Make footers position fixed, so that its content appears