Enable 1.0/2.0 zoom by default
Enable zoom functionality matching stable branch features also in master by default. Have the configure option for experimental zoom support to control only functionality that is additional compared to stable branches.
The zoom functionality is not visible in gtk3.22 (in S3_0)
I discovered it recently when trying qt client, which show it in a menu, with shortcuts + / - , then i tried in gtk, and it works
It is a really ussefull feature (even more with this patch), i think it should be shown somewhere in the GUI menus in gtk-client-* like in qt-client