[Utils] DOSBox Update

DOSBox 0.70

Another year and another dosbox version, again more speedups and compatibility fixes.

Speed up the dynamic cpu core (certain games get much faster).
Added a dynamic fpu on x86 hosts.
Improved the cycle guessing code (and make it default).
Better and more configurable joystick support.
Improved the image and fat drives.
Added nullmodem emulation.
Various win 3.x enhanchments (video/audio/ems/win32s).
Improved CDROM detection and support.
Speed up the screen drawing code.
Added support for different keyboard layouts.
Various fixes to the (C/E/V)GA emulation.
Extended and improved all types of emulated memory. (umb/ems/xms)
Dynamic core should work on Intel Macs.
Various timer related fixes.
Added a few more graphic scalers.