rework Makefile

- allow user to use a different pkg-config binary
- restore almost all (and add other ones) warning flags (-Werror is not set)
- $(XWAYLAND) is added to our CPPFLAGS
- remove useless comments
- don't generate idle-protocol.h (not used)

append `-dev` to $(_VERSION) (should have added it a long time ago)

use `git describe` to generate version

include xcb only when building with xwayland support

convert makefile to be more portable

add flag to print version and exit

don't let -pedantic be overridable by environment

new functions ecalloc() and die()

die() replaces EBARF and BARF
and allow us to add `-pedantic` to CFLAGS

Merge pull request #180 from Humm42/manpage

add dwl(1)

Merge branch 'main' into scenegraph

add dwl(1)

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

don't warn about unused result

Closes: #186

XWayland still buggy, disable by default

consolidate some of the ugliness into a separate file

Similar to Linux kernel approach, encapsulate some of the uglier
conditional compilation into inline functions in header files.

The goal is to make dwl.c more attractive to people who embrace the
suckless philosophy - simple, short, hackable, and easy to understand.
We want dwm users to feel comfortable here, not scare them off.  Plus,
if we do this right, the main dwl.c code should require only minimal
changes once XWayland is no longer a necessary evil.

According to `cloc`, this also brings dwl.c down below 2000 lines of
non-blank, non-comment code.

let's not alienate the dwm folks

Fix style.

Merge pull request #65 from Keating950/master

Add install target to Makefile

add install target to Makefile and corresponding prefix variable to config.mk

add install target to Makefile and corresponding prefix variable to config.mk

Merge pull request #1 from djpohly/master

Pull Request

Merge branch 'master' into 31-independents-mouse-focus