"Follow" indicator

[nickbnf]

Add an icon indicating "follow" mode is active, maybe a little down arrow a la BareTail.

[hiredgunhouse]

I miss this feature a lot since it's very easy to disable "follow" mode by scrolling.

[Kuba15]

I just discover this issue, but I have already just proposed this: #51

It is a checkbox in the tool bar before the "info line".
So the Follow file can also be quicker activated via the mouse.

The idea of the down arrow could be managed via a specific checkbox icon when checked :)
Would be more visual.