- add new portable display_error (and convenience macro DISPLAY_ERROR,
if advanced params aren't needed; don't want to break C compat). this is
the old assert dialog and more; allows ErrorReaction (see sysdep.h) to
be carried out according to users wishes.
- add win_is_locked for deadlock avoidance
This was SVN commit r2420.
- sysdep/debug.h includes platform-specific version, so they can define
debug_break
- no longer a debug_break wrapper that calls to specific versions (so
that the debugger breaks in the target function directly)
- unix-specific stuff is only debug ATM; call it udbg instead of unix.*
This was SVN commit r1813.