Improved build scripts.

The scripts now have more sensible names, and the code is better factored.

dist/releasescript

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+BUILDER=./build-arch-tag
+
 # Check whether the tag exists
 TAG=$1
 if [ "x$TAG" != "x" ]
@@ -29,11 +31,11 @@ fi
 OS=`uname -s`
 if [ "x$OS" = "xDarwin" ]
 then
-	./gitdist.sh mac $TAG
+	$BUILDER mac $TAG
 elif [ "x$OS" = "xLinux" ]
 then
-	./gitdist.sh linux $TAG
-	./gitdist.sh w32 $TAG
+	$BUILDER linux $TAG
+	$BUILDER w32 $TAG
 else
 	echo "Don't know architecture $OS, where am I?"
 	exit