Merge pull request #1 from halton/master

Add support to specify root_dir
chromium64.py: Change patches
chromium64.py: Refine mk64
chromium64.py: Use bash to generate .mk files
chromium64.py: Add option of one job build
chromium64.py: Support x64 as target arch
chromium.py: Add global variable target_arch
android.py: Support multiple devices and versions
version.py: Add script to set version
install.py: Remove JDK description
.zshrc: Comment out JAVA_HOME
android.py: Describe correct jdk version to build
install.py: Remove blank line
version.py: Change directory
util.py: Add as shared util file
version.py: Use util.py
android.py: Use util.py
chromium.py: Use util.py
skia.py: Use util.py
version.py: Add support of gcc