From John Marraffino:

1.  DispatchSignals(sig)
    Replace call to Abort(-1) with a call to Exit(sig) to
    allow CMSSW to flush buffers, close files and clean up
    after a fatal error.

2.  StackTrace()
    Enlarge string field widths to accommodate long function
    signatures for demangling.

    Enable use of GNU script, gstack, if available. Replace
    incorrect sed script in gstack. Modified gstack is available
    as $ROOTSYS/etc/gdb-backtrace.sh.

    Increase sizes of buffers for calls to and responses from
    the addr2line and cppfilt functions.

    The addr2line function doesn't know about paths so every
    library or executable name passed to it must include a full
    path. This is automatic for shared libraries. On the other
    hand, for main programs specified without a path, send
    `which main` and let the shell expand the name for us.

    For shared libraries, addr2line wants an offset into the
    file.  For main programs, it wants the absolute virtual
    address. Distinguish between these two cases and send
    the correct address.


git-svn-id: http://root.cern.ch/svn/root/trunk@17026 27541ba8-7e3a-0410-8455-c3a389f83636