Add target-dir arg support to dev-build script

This patch provide a custom TARGET_DIR feature to dev-build.sh script.
When not specified, TARGET_DIR value defaults to publish. With this
patch dev-build /your-custom-directory format is supported so
distribution build destination directory can be different from
publish.

Change-Id: Icd561748b7909b8d114be311bee4118e0e582e20