This is an X type and should be internal to x.c.

The selcopy() function was a single line and only used in one place, so
it was inlined to reduce LOC.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

There was only a single reference to the `win` variable in st.c, so
exporting that to x.c allows us to rid ourselves of another extern.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

No need to keep a function that only calls another function in the same
file.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

config.h includes references to KeySyms and other X stuff.  Until we
come up with a cleaner way to separate configuration, it is simpler
(leads to more code removal) to have this here.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

xresize is now internal to x.c

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

This allows us to make xseturgency internal.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

This makes x(un)loadfonts internal to x.c.  Needed to reorder includes
and move a typedef to keep the compiler happy.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

run/usage/xinit are now all internal to x.c

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

This makes xsetenv internal to x.c, and allows iso14755's external
command to use $WINDOWID instead of having to snprintf it again.  (The
same benefit will apply to the externalpipe patch.)  The xwinid function
is no longer needed.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

This is used by, e.g., tmux.