Add top level build script for building packages.

ports/snes9x/build.sh

 #!/bin/bash
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
-#
 
-# nacl-snes-1.53.sh
-#
-# Usage:  nacl-snes-1.53.sh
-#
-# This script downloads, patches, and builds an snes9x-based SNES emulator for
-# Native Client.
-
-source pkg_info
 PACKAGE_DIR=${PACKAGE_NAME}-src
-source ../../build_tools/common.sh
+SRC_DIR=${NACL_PACKAGES_REPOSITORY}/${PACKAGE_DIR}
+BUILD_DIR=${SRC_DIR}/${NACL_BUILD_SUBDIR}
 
 EXECUTABLES=snes9x
 NACL_CONFIGURE_PATH=${NACL_PACKAGES_REPOSITORY}/${PACKAGE_DIR}/unix/configure
 EXTRA_CONFIGURE_ARGS="\
       --disable-gamepad \
       --disable-gzip \
       --disable-zip \
       --disable-jma \
       --disable-screenshot \
       --disable-netplay \
       --without-x \
       --enable-sound"
 export LIBS="${NACLPORTS_LDFLAGS} -lppapi_simple -lnacl_io -lppapi_cpp -lppapi"
 
 AutogenStep() {
   echo "Autogen..."
   pushd ${NACL_PACKAGES_REPOSITORY}/${PACKAGE_DIR}/unix
   autoconf
   PatchConfigure
   PatchConfigSub
   popd
 }
 
 ConfigureStep() {
   AutogenStep
   DefaultConfigureStep
 
   # This configure script generates a Makefile that checks timestamps on
   # configure.ac, configure and Makefile.in. Copy them from the unix directory.
-  cp ../unix/{configure.ac,configure,Makefile.in} .
+  LogExecute cp ../unix/{configure.ac,configure,Makefile.in} .
   touch Makefile
 }
 
 InstallStep(){
-  local SRC_DIR=${NACL_PACKAGES_REPOSITORY}/${PACKAGE_DIR}
-  local BUILD_DIR=${SRC_DIR}/${NACL_BUILD_SUBDIR}
   MakeDir ${PUBLISH_DIR}
   install ${START_DIR}/snes9x.html ${PUBLISH_DIR}
   install ${START_DIR}/snes9x.js ${PUBLISH_DIR}
   install ${BUILD_DIR}/snes9x ${PUBLISH_DIR}/snes9x_${NACL_ARCH}${NACL_EXEEXT}
 
   python ${NACL_SDK_ROOT}/tools/create_nmf.py \
       ${PUBLISH_DIR}/snes9x_*${NACL_EXEEXT} \
       -s ${PUBLISH_DIR} \
       -o ${PUBLISH_DIR}/snes9x.nmf
 
   if [ "${NACL_ARCH}" = "pnacl" ]; then
     sed -i.bak 's/x-nacl/x-pnacl/' ${PUBLISH_DIR}/snes9x.js
   fi
 }
-
-PackageInstall
-exit 0