use sigaction(2) for signal handling

References: http://git.suckless.org/dwm/commit/712d6639ff8e863560328131bbb92b248dc9cde7.html

bump version to 0.4

remove `--long` from git-describe command

return early if selmon is not part of the output layout in dirtomon()

instead of checking twice

simplify check in urgent()

we only care if it returned a client or not

arrange monitor after updating fullscreen background and lock surfaces

also update locked_bg node position in updatemons()

add blank lines to make updatemons() more readable

update comment about client_set_size() as no-op

check if a client is resizing before checking if it's visible

It's not like it's noticeable, but theoretically this is faster

only mark pending resizes as completed checking the configure serial

bump version to 0.4-rc3

do not try to resize if size wouldn't change

do not skip frames if a client is stopped and have a pending resize

Revert "Revert "fix flickering when resizing/spawning windows""

This reverts commit 4a32293548667e68cd9a103e22368b8db1754deb.

disable client's scene node after create it (only XDGShell)

will be enabled when setting up its monitor and arrange it

Bug: https://github.com/djpohly/dwl/issues/306

call arrange() or resize() depending on c->isfloating in commitnotify

force SSD when creating an xdg_toplevel_decoration object

Closes: https://github.com/djpohly/dwl/issues/366
Not sure why GLFW apps do not get mapped when we do not tell them the
decoration method

remove selclient()

selclient() does not work well when dealing newly mapped
clients (specifically those mapped on invisible tags).

This fixes various bugs related to things not working because selclient() would
return NULL.

References: 94c8bd604870365bc201524b63158623e6f32a8f

fix unset fullscreen for all visible clients when mapping a new one

this also changes our policy about when we unset fullscreen:

dwl will unset fullscreen for clients who share tags (and monitor) with a newly
mapped client, it does not matter if the clients are visible or not