Huge DPMI update (not too much user-visible though).
- First step to Blinker extender support - PM API translator now uses the
EMS page frame to save 64K of conventional memory.
- $_pm_dos_api option introduced which allows to disable the API translator
(Bart wanted to preserve the possibility of disabling EMS and getting an
extra UMB space without disabling also DPMI).
- First step at solving bug #902742 (most is_dos_selector() checks removed,
but not all).
There are lots of internal changes made, for example exec'd DPMI program is
now "forked" as a separate DPMI client. Memory structures were changed to
allow sharing allocations between parent and child clients. And more...
Just watch out for a bugs now:)


git-svn-id: https://dosemu.svn.sourceforge.net/svnroot/dosemu/trunk@370 7758b857-130e-0410-ab9c-d8735a528d18