Xd 739 - Eliminate internal dependency on system properties. Use Spring Environment abstraction

- Renamed all xd configuration properties that can be set externally from xd.*  XD_*
- Enhanced command line option framework to detect which option values are explicitly set as command line arguments. Also, additional unit tests.
- Added configuration logic to map options to property values,  eliminating implicit option values if the corresponding property is set in a System property or Environment variable before invoking Environment.propertySources.addFirst()
- Added configuration hook OptionUtils.configureEnvironment where appropriate
- All runtime components reference environment as the source instead of options
- Added environment configuration to BeanDefinitionAddingPostProcessor
- Have smoke tested with SingleNode Rabbit and Redis environments. Better testing of scripts is needed.