Direct3D in full-screen mode now transfers control of input to the full screen window, fixes #429;

Unified screenshot code and moved it to video.c, it is now independent of both renderer and platform;
The EGA/(S)VGA overscan now also works for CGA, PCjr, Tandy, and CGA-using Amstrads;
Fixed EGA/(S)VGA overscan operation so it works correctly with scrolling and panning;
Fixed 320x200x32K and 320x200x64K modes on the ET4000/W32p;
Fixed the Video 7 1024i chip ID and video memory options, fixes #431;
Fixed a banking bug in the S3 cards, fixes Windows 9x and NeoPaint.

src/win/Makefile.mingw

@@ -186,15 +186,6 @@ endif
 ifndef DINPUT
  DINPUT		:= n
 endif
-ifndef D3DX
- D3DX		:= y
- ifeq ($(ARM), y)
-  D3DX		:= n
- endif
- ifeq ($(ARM64), y)
-  D3DX		:= n
- endif
-endif
 ifndef OPENAL
 OPENAL		:= y
 endif
@@ -274,7 +265,7 @@ else
 TOOL_PREFIX     := i686-w64-mingw32-
 endif
 CPP             := ${TOOL_PREFIX}g++
-CC              := ${TOOL_PREFIX}gcc
+CC              := gcc
 WINDRES		:= windres
 STRIP		:= strip
 ifeq ($(ARM64), y)
@@ -435,10 +426,6 @@ ifeq ($(DINPUT), y)
 OPTS		+= -DUSE_DINPUT
 endif
 
-ifeq ($(D3DX), y)
-OPTS		+= -DUSE_D3DX
-endif
-
 # Options for the DEV branch.
 ifeq ($(DEV_BRANCH), y)
 OPTS		+= -DDEV_BRANCH
@@ -733,9 +720,6 @@ ifeq ($(DINPUT), y)
 else
  LIBS    += -lxinput
 endif
-ifeq ($(D3DX), y)
-LIBS    += -ld3dx9
-endif
 
 ifeq ($(STATIC), y)
 LIBS    += -static