Remove GUI-related API from libdevhelp
There are too many widgets in the API; they leak the details of how Devhelp is put together, and they become part of the API/ABI to the point that it gets progressively harder to change what really amounts to an implementation detail.
For instance: DhTab
is a GtkGrid
, instead of being a GtkBin
with a GtkGrid
inside it. To be fair, there's literally no reason why it should be a container to begin with, but GtkBin
is probably the easiest widget we can make with GTK3.