left-click on libappindicator indicators

[Raman Gupta]

Currently (or at least as of Plasma 5.5.5 on my Fedora 23 machine),
left-click on libappindicator-based indicator's in the plasma system
tray does.... absolutely nothing.

An example of this indicator is pidgin with the pidgin-indicator
plugin (https://github.com/philipl/pidgin-indicator).

On Ubuntu Unity, both left and right-click apparently open the
indicator menu. Personally I am not fond of this behaviour, but it is
better than doing nothing.

I would prefer if Plasma could detect whether a tray icon provides a
window, and if so, Plasma did application show/hide when tray icons
are left-clicked. Essentially a minimize to tray/restore from tray
function. Thoughts?

Regards,
Raman