Cleaned up vm86plus.h. Created a new init_handler function in signal.c
which takes care of flags, %fs, %gs etc. dis8086 64-bit compat. Create
dpmi_iret_setup for exiting signal handlers to DPMI client code.


git-svn-id: https://dosemu.svn.sourceforge.net/svnroot/dosemu/trunk@1619 7758b857-130e-0410-ab9c-d8735a528d18