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?)

dat/opthelp

@@ -163,6 +163,9 @@ autounlock    when attempting to open a locked door or loot     [Apply-Key]
               omitted or skipped and Apply-Key is omitted or you aren't
               carrying an unlocking tool or you decline to use one
 boulder       override the default boulder symbol                       [`]
+crash_email   email address to use when filling in crash reports         []
+crash_name    name to use when filling in crash reports                  []
+crash_urlmax  length of longest url we can generate for a crash report   []
 disclose      the types of information you want         [ni na nv ng nc no]
               offered at the end of the game
               (space separated list of two-character values;