Bug 1025055 - support passing packages and unpacking them on the client. r=ted
        - Refactored option parsing for -binary and -package
        - Use posixpath for paths on the client.
        - Refactor to have the asset provide the test root. Have the asset
        calculate its remote path.
        - Rename all instance variables in the ApplicationAsset so as to hide
        them and have getters that work.
	- Extra error handling in mounting disk images.