Add xorg.conf IgnoreABI option which does the same thing as -ignoreABI

hw/xfree86/common/xf86Config.c

@@ -761,7 +761,8 @@ typedef enum {
     FLAG_RENDER_COLORMAP_MODE,
     FLAG_HANDLE_SPECIAL_KEYS,
     FLAG_RANDR,
-    FLAG_AIGLX
+    FLAG_AIGLX,
+    FLAG_IGNORE_ABI
 } FlagValues;
    
 static OptionInfoRec FlagOptions[] = {
@@ -833,6 +834,8 @@ static OptionInfoRec FlagOptions[] = {
 	{0}, FALSE },
   { FLAG_AIGLX,			"AIGLX",			OPTV_BOOLEAN,
 	{0}, FALSE },
+  { FLAG_IGNORE_ABI,			"IgnoreABI",			OPTV_BOOLEAN,
+	{0}, FALSE },
   { -1,				NULL,				OPTV_NONE,
 	{0}, FALSE },
 };
@@ -891,6 +894,10 @@ configServerFlags(XF86ConfFlagsPtr flagsconf, XF86OptionPtr layoutopts)
 		      &(xf86Info.grabInfo.allowDeactivate));
     xf86GetOptValBool(FlagOptions, FLAG_ALLOW_CLOSEDOWN_GRABS,
 		      &(xf86Info.grabInfo.allowClosedown));
+    xf86GetOptValBool(FlagOptions, FLAG_IGNORE_ABI, &xf86Info.ignoreABI);
+    if (&xf86Info.ignoreABI) {
+	    xf86Msg(X_CONFIG, "Ignoring ABI Version\n");
+    }
 
     /*
      * Set things up based on the config file information.  Some of these

hw/xfree86/common/xf86Init.c

@@ -331,6 +331,10 @@ InitOutput(ScreenInfo *pScreenInfo, int argc, char **argv)
     /* Tell the loader the default module search path */
     LoaderSetPath(xf86ModulePath);
 
+    if (xf86Info.ignoreABI) {
+        LoaderSetOptions(LDR_OPT_ABI_MISMATCH_NONFATAL);
+    }
+
 #ifdef TESTING
     {
 	char **list, **l;

hw/xfree86/common/xf86Privstr.h

@@ -166,6 +166,7 @@ typedef struct {
     MessageType		randRFrom;
     Bool		aiglx;
     MessageType		aiglxFrom;
+    Bool        ignoreABI;
     struct {
 	Bool		disabled;		/* enable/disable deactivating
 						 * grabs or closing the

hw/xfree86/doc/man/xorg.conf.man.pre

@@ -605,6 +605,10 @@ the builtin handler will be used.
 .TP 7
 .BI "Option \*qAIGLX\*q \*q" boolean \*q
 enable or disable AIGLX. AIGLX is enabled by default.
+.TP 7
+.BI "Option \*qIgnoreABI\*q \*q" boolean \*q
+Allow modules built for a different, potentially incompatible version of
+the X server to load. Disabled by default.
 .SH MODULE SECTION
 The
 .B Module