bug#14233: 24.3; Don't constrain frame size to character multiples

[martin rudalics]

> Hmm...  I guess character-size increments of the frame might still
> make sense at least in some use cases, because from the user POV, not
> every size change is meaningful.  E.g., a user could want to have N
> extra lines or columns.  But OTOH, these goals are perfectly
> achievable with pixel-unit resizes.  So it's not clear to me what
> would be the benefit of keeping character-size increments.

As explained earlier, I still keep character-size increments for window
based resizing.  When resizing a window combination I give all windows
but at most one a multiple of the default character size.

> Martin, do we have any important use cases beyond fullscreen where
> pixel-unit resize of frames is really necessary?

We have three use cases: Requests from tiling WMs, maximization requests
which leave the taskbar visible and are triggered, for example, when the
taskbar gets resized or auto-hidden, and fullscreen requests which ask
for hiding everything else.  IIUC the most common ones are maximization
requests.

martin