[NTVDM]
- Support loading executables with the old EXE signature ('ZM' instead of 'MZ').
- Fix the EXE loader so that:
* we can load programs of >= 1Mb size, by exploiting the fact that on real DOS, the computed exe size (which uses the number of 512-byte blocks, stored in the EXE header) is stored in a WORD variable.
This has as an effect to truncate the value, and if it is such that the truncated value is less than the size of available memory, the EXE can be loaded (partly, of course). Some apps expect this behaviour,
for example, Turbo C++ IDE.
* Simplify the memory limits computation, according to http://www.tavi.co.uk/phobos/exeformat.html , which is the correct algorithm used by DOS (and confirmed by FreeDOS also).
svn path=/trunk/; revision=69261