For the SBBS binaries, set @executable_path and
@executable_path/../${LIBODIR} so they can all be in one dir, or
they can be in the build output dirs and still work.

For utilities, set to @executable_path and
@executable_path/../../${LIBODIR} for the same reason.

With this, we shouldn't need to fiddle with DYLD_LIBRARY_PATH

Remove the -E linker flag.
This should not be needed anymore, and isn't supported on macOS.

Have shared libraries include their full path.
This allows linked dylibs to work from where they were built, so
as long as you don't build the binaries on a CI machine, then try
to run them on a users machine (*cough*), it'll work out.

Use the correct rpath argument format on macOS.
It uses -rpath, not --rpath.

Don't return an error if the node#/node.cnf file can't be opened for all uses of load_cfg() except from the terminal server. This fixes #214 for Tracker1

gtkmonitor.c:156:79: warning: iteration 9 invokes undefined behavior [-Waggressive-loop-optimizations]
   sprintf(str,"%-2d  SL: %-2d  F1: %s",i,cfg.val_level[i],ltoaf(cfg.val_flags1[i],flags));
                                                                 ~~~~~~~~~~~~~~^~~
gtkmonitor.c:151:2: note: within this loop
  for(i=1; i<=10; i++) {
  ^~~

not set (or blank), use the default ("/sbbs/ctrl") and print a warning to
stderr. This resolves a FAQ for sysops that struggle with setting the SBBSCTRL
env var, but do have sbbs install in /sbbs or a symlink from /sbbs to where
sbbs is actually installed.

Note: this function is different than the one previously defined in getctrl.c
but never used. If/when we ever really need to support PREFIX, then perhaps
we'll use that one (which copies a string to a buffer).

targets.mk:8: *** missing separator (did you mean TAB instead of 8 spaces?).  Stop.

about undefined targets.

GtkBuilder era.

Thanks rfrederick!