Added more things to x86_64 image.

Some preference apps, mount_server and AboutSystem. Removed the check
for x86_64 in the boot script, the normal path through the script will
work now. Also removed a temporary hack to workaround AboutSystem not
being there in build_haiku_image.

build/scripts/build_haiku_image

@@ -329,8 +329,6 @@ fi	# ! updateOnly
 # add the concatenated copyrights as an attribute to AboutSystem
 
 if [ ! $updateOnly ]; then
-# TODO x86_64: temporary hack, AboutSystem doesn't exist yet.
-if [ -f $outputDir/objects/haiku/*/*/apps/aboutsystem/AboutSystem ]; then
 	if [ -f $copyrightsFile ]; then
 		copyrightAttrs=$tmpDir/copyrightAttrs
 		$rmAttrs -f $copyrightAttrs
@@ -339,7 +337,6 @@ if [ -f $outputDir/objects/haiku/*/*/apps/aboutsystem/AboutSystem ]; then
 		$copyAttrs ${sPrefix}$copyrightAttrs ${tPrefix}system/apps/AboutSystem
 	fi
 fi
-fi
 
 if [ $isCD ]; then
 	# generate the attribute stores