add CRASHREPORT directly to browser

add CRASHREPORT for Windows
add ^P info to report (via DUMPLOG)

new options: crash_email, crash_name, crash_urlmax
new game command: #bugreport
new config option: CRASHREPORT_EXEC_NOSTDERR
new command line option: --bidshow

deleted helper scripts:
    NetHackCrashReport.Javascript
    nhcrashreport.lua

misc:
    update CRASHREPORTURL (will need to be updated before release)
    update bitrot in winchain
    winchain for Windows
    add missing synch_wait for NetHackW --showpaths
    add PANICTRACE (and CRASHREPORT) in mdlib.c:build_opts

missing:
    packaging (Windows needs the pdb file)
    no testing with MSVC command line build

port status:
    linux: working, but glibc's backtrace doesn't show static functions
    Windows VS: working.  pdb file is large - looking into options
    MacOS: working
    msdos: not supported
    VMS: not supported
    MSVC: planned, but not attempted
    MSYS2: working, but libbacktrace not showing symbols (yet?)

src/decl.c

@@ -272,6 +272,10 @@ const struct instance_globals_c g_init_c = {
     DUMMY, /* context */
     /* dog.c */
     DUMMY, /* catname */
+    /* end.c */
+    NULL, /* crash_email */
+    NULL, /* crash_name */
+    -1, /* crash_urlmax */
     /* symbols.c */
     0,     /* currentgraphics */
     /* files.c */