- fix link to README file
- silence compiler warning with (int) cast in str_device_OS_UDID()
- add str_iOS_version(), rename two others to str_logTime() and str_logDate()
- reenable OverlayRender methods
- add code to implement overlayRenderer methods for demo 2
- clear out commented-out 'dead' code
- add more end-user (i.e., developer) comments
- disable most logging code (but leave in place for future development)
- TODO: still need to implement MapUserTrail class