Readme: achieve fullscreen + allow borderpx = 0

Quit fullscreen on new x11 window

After the removal of quitfullscreen() dwl wouldn't compile widh xwayland
enabled because createnotifyx11 was still using the old function

Delete quitfullscreen()

quitfullscreen() was replicating the functionalities of setfullscreen(c,
0)

Reusing setfullscreen() in quitfullscreen() leads to a 3 line function,
which is useless since quitfullscreen() is used once anyway

Keep windows fullscreen after redraw

This fixes the bug that happens when changing workspace (or any time
arrange() is called) where there are fullscreen windows, which are still
fullscreen but leave the space for layer surfaces like waybar (which
should be hidden when going fullscreen)

Also as soon one fullscreen window is found hte function returns to
improve efficiency

Set fullscreen simpler

use m->m (fullscreen on top of layers)

fix typo

Allow borderpx = 0

Toggle fullscreen on all clients

mod+e allows to toggle fullscreen any client, even those who don't
support it themselves

Handle new windows

Windows lose fullscreen state when a new window is created in the same
tag

isfullscreen int

Same fscreen func for xdg and xwayland

Fullscreen xwayland

Unlink fullscreen

Restore windows after fullscreen

Store position and size of windows before going fullscreen. This is more
efficient than arrange() and also works with floating windows

All the clients keep their original position because arrange() isn't
used after quitting fullscreen

No borders on fullscreen windows

Some code has been borrowed from the smartBorders patch

Toggle fullscreen

Basic fullscreen

handle the x11 configure event

This fixes the window size of old games in Wine.

implement the virtual keyboard protocol

This is used by wtype.

Also properly cleanup keyboards. Without wl_list_remove(&kb->link) dwl
crashed after using wtype 2-3 times.