Need testing on big-endian machines. We may be missing some LEnn_CPU()
calls.

pst2diii needs header and mime type updates from readpst.

At the next soname bump (to libpst.so.5) we should
    remove readpstlog, and produce ascii debug log files
    try fork() with child limit to get parallel readpst
    move some of readpst into the shared library, in particular write_normal_email()
    add helper function item_actual_type (mail, contact, etc)
    change gmtime() and ctime() to _r versions for thread safe operation
    <http://www.geocities.com/cainrandom/dev/MAPIRecurrence.html>