[dwm] [pull request] arguments for ClkTagBar functions

This little pull request just add a buttons[i].arg.i == 0 check in the
buttonpress function.
There is no reason you cannot pass arguments to the ClkTagBar
functions. With this pull request it is possible to use your middle mouse
button to view prev or all tags, or the wheel to change the focused
client. Any chance it can enter in main dwm before 5.2?

As a side note, don't you think this is a much less conforspacele way to
tag clients with the mouse?
        { ClkTagBar, Button2Mask, Button1, tag,
       {0} },
        { ClkTagBar, Button2Mask, Button3,
toggletag, {0} },

I have never tagged clients with MODKEY+Mouse, I don't know if you use to do it.
slds,

-- 
- yiyus || JGL .