pass arguments to xbuild so that we can easily run /t:Clean.

Author: Atsushi Eno

build.sh

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 for dir in `find . -type f -name *.csproj`; do
-	xbuild $dir;
+	xbuild $dir $@;
 
 	if [ $? != 0 ]; then
 		exit 1;