First of all, really great work!
I tried the DrawingTestPal example of your library with the Arduino Ide 1.5.2 on my Arduino Due, but it show me this error :
In file included from DrawingTestPAL.ino:1:
C:\Users\andrea\Desktop\Andrea\Arduino\arduino-1.5.2\libraries\VGA/VGA.h: In function 'void _v_digitalWriteDirect(int, boolean)':
C:\Users\andrea\Desktop\Andrea\Arduino\arduino-1.5.2\libraries\VGA/VGA.h:49: error: 'g_APinDescription' was not declared in this scope
C:\Users\andrea\Desktop\Andrea\Arduino\arduino-1.5.2\libraries\VGA/VGA.h:50: error: 'g_APinDescription' was not declared in this scope