display-application; Set fancy printing parameters individually
for different types of display (backtrace, error, application).
(These should of course be customizable!)
old scm_sysintern but doesn't take a second value argument.
(scm_sysintern): Now uses scm_sysintern0.
(scm_sysintern_no_module_lookup): Renamed to
scm_sysintern0_no_module_lookup and doesn't take a second value
argument any longer.
* symbols.h (scm_sysintern0: Added declaration.
* options.c (scm_init_opts): Use scm_sysintern0 instead of
scm_sysintern when interning option keys. Otherwise we risk
destroying the values of already interned variables.
* symbols.c (scm_sym2vcell): Bugfix: Treat definedp as
scheme-level boolean (use SCM_NFALSEP).
* backtrace.c (scm_init_backtrace): Make Scheme-level variable
`the-last-stack'.
(scm_backtrace): New function. (C version of old function from
boot-9.scm) Motivation: Make it possible to display backtraces
without depending on boot-9.scm. (I'm uncertain if this
motivation is good enough...)
* root.h (scm_root_state): Add member the_last_stack_var.
(scm_the_stack_var): Defined to scm_root->the_last_stack_var.
* root.c (mark_root): Mark scm_the_last_stack_var.
* init.c (scm_start_stack): Initialize scm_the_last_stack_var to
SCM_BOOL_F.
renamed from display_error_message.
* backtrace.h (scm_display_error_message): Added extern decl.
* throw.c (uncaught_throw): Use it to display the error message.
