CB-6756 Adds save and restore command for platforms.

It also enhances the ConfigParser to support engine elements and cordova namespace.

Conflicts:
	cordova-lib/spec-cordova/restore.spec.js
	cordova-lib/src/configparser/ConfigParser.js
	cordova-lib/src/cordova/restore.js
	cordova-lib/src/cordova/save.js

github: close #18