Open files in binary mode to disable text translation

To ensure the correct handling of binary files under Windows, all file
opens now force binary mode.
Updated to use file_open macros, reducing original code changes

Use of the O_BINARY flag still depends on whether it's available,
rather than a build environment or platform check.
Changed file_open to use GCC variadic macro

Also changes the conditional use of O_BINARY to the MINGW32 build system.
Merge pull request #24 from simonowen/binary

Open files in binary mode to disable text translation
Cleaner definition of non-Windows version of file_open().
Fix win32 msys build
Merge pull request #25 from Lord-Nightmare/master

Fix for building on win32 mingw-msys
Create posix_mkdir() abstraction over environment-dependent mkdir()
disk-analyse: Fix bogus memfree() of arithmetic-adjusted data pointer.
libdisk: Libraries must follow source files on link command line
libdisk: Mark uninitialised ADF track as all-sectors-invalid
e-uae-patches: Remove e-uae patches.
My e-uae changes are now managed in a separate github repository.
m68k_emulate: Decode and emulate 0xAxxx and 0xFxxx opcodes as A|F-line exceptions
m68k_emulate: Emulate the ABCD/SBCD arithmetic opcodes
m68k/amiga: Do not log polled reads of intreqr
m68k/amiga: Fix emulation of disk head stepping
libdisk: Support Albedo by Myriad/Loriciels
disk-analyse: Define formats of "Uninvited" and "Victory Road"
Added new Formats to support WJS Design Games: Anarchy, Baal, Beastlord, Creatures, Ork, and Spell Bound
Updated the Fun_Factory format to support Gadgets Lost In Time