I was looking into adding a confirmation prompt for '!' and it
isn't very promising due to sequencing issues. (The check for
whether '!' is allowed should happen before the prompt about
running it but the latter should take place in the core rather
than in the port code.) In the mean time, I noticed that VMS was
ignoring the SHELLERS value from SYSCF.
Untested implementation of a SHELLERS check on VMS. Even if it
works, it should not be using $USER as the user name to verify.
Tweaks the Unix implementation of check_user_string() but doesn't
switch the testing loop to the simpler version used by VMS which
is derived from the generic users test used by Qt.
When stopping in the debugger after having called impossible, the windowing
state will have been modified since the assertion was hit. This made
examining state that caused the nhassert to fire no longer possible.
To avoid this issue, we now detect the debugger and stop in the debugger
prior to impossible.
Because some Makefile.top dependencies triggered the build
of the host native lua library, the cross-compiles were
building it needlessly.
Make it a make variable so that it can be overridden by
cross-compile recipes in sys/unix/hints/include/cross-*.2020
Replace use of $(LINK) with $(CLINK) or $(CXXLINK) as warranted.
When the Qt interface is enabled, the utility programs were all
(except dlb) being linked with C++ support. That didn't cause
any problems, just looked wrong. Link them as C instead of C++.
Two actually do need C++ support (and still have it) but both
are dead: 'tile2beos' because the source file doesn't exist (not
even in 'outdated'), 'tileedit' because it won't build with Qt5.
I didn't bother with QUIETCC support for them.
There were still a couple of references to dgn_comp (for the lint
target; just in the name of a macro, not its value); remove those.
