Create wrappers for MacOS/Linux to allow sdk "binaries" to be

sdk/bin/pub

+#!/bin/bash
+# Run pub.dart on the Dart VM. This script assumes the Dart SDK's directory
+# structure.
+
+# Setting BIN_DIR this way is ugly, but is needed to handle the case where
+# dart-sdk/bin has been symlinked to. On MacOS, readlink doesn't work
+# with this case.
+CUR_DIR="$(cd "${0%/*}" ; pwd -P)"
+export DART_SDK="$(cd "${CUR_DIR%/*}" ; pwd -P)"
+
+if [ -z "$DART_VERSION" ];
+then
+  DART_VERSION="ReleaseIA32"
+fi
+
+if [[ `uname` -eq 'Darwin' ]]; 
+then
+  BIN_DIR="$CUR_DIR"/../../xcodebuild/$DART_VERSION
+else
+  BIN_DIR="$CUR_DIR"/../../out/$DART_VERSION
+fi 
+
+exec "$BIN_DIR"/dart "$DART_SDK"/../utils/pub/pub.dart $@