OS detection
------------

During startup QLIB will try and detect the current OS.
_os_typ will hold what was detected.
_os_ver_major and _os_ver_minor will hold it's version
_dos_ver_major and _dos_ver_minor will always hold DOS's version

These are defined in os.h (and os.inc)
Name     Description
----     -----------
OS_DOS   MS-DOS
OS_WIN   Windows 3.x
OS_WIN95 Windows NTv4.0/95
OS_WINNT Windows NTv3.x   (v4.0 not detected yet)
OS_DV    Desqview
OS_OS2   OS/2  (not detected yet)

As you can see some OSes are not yet detected.  I need some code!