make sure to leave XWayland process waitable

On SIGCHLD, check to make sure the terminated process is not the
XWayland process before reaping it, allowing wlroots to waitpid() for it
successfully.

Fixes #177.

createpointer now takes wlr_pointer

createkeyboard now takes wlr_keyboard

destroy scene_output in cleanupmon()

fix drag icon's surface returned by xytonode

set position of the drag icon in startdrag()

Revert "clients now works as expected in drag motion"

This reverts commit 9aec6049ecbefe3618f34002d2239cc9462c07e9.

this problem is caused because xytonode() returns the surface of the
drag icon

inline the presentation variable

This variable can be removed since with scene-graph
wlr_presentation_surface_sampled_on_output no longer needs to be called.

add note about how to change MODKEY for windows key

Fix dwl freezing when resizing

Add a configuration option for fullscreen locking

Some people are annoyed to have this new behaviour forced for some
application which use fake fullscreen.

add sway LICENSE file

part of the code in dwl is taken from sway, so credit it.
dwm and sway are both licensed under the MIT license

update IRC channel

add dwl(1)

Documentation is good.  Man pages are documentation.  A program without
a man page is worthless.

clients now works as expected in drag motion

implement drag and drop

For brevity, only a single drag icon at a time is supported.

Co-authored-by: Leonardo Hernández Hernández <leohdz172@protonmail.com>

Update issue templates

only skip frames if there are visible clients that have a resize

remove a useless resize in mapnotify()

applyrules() calls setmon() which calls resize()

improve floating detection

mostly copied from sway