Rewrote capture routines, added Settings.java and bug fix:

- capture routines re-implemented so they now support switching from
front camera to back camera
- implemented defensive programming throughout Capture.java
- added more in app status checks in the capture routines
- Modified Continue button in capture.java so it changes to "Wait" if
busy
- Settings.java implements methods to save/restore data between
activities so i could get the multiple cameras working
- capture routines now obey saved settings
- fixed the render and share intents so they pass the files correctly to
the selected apps
- Updated main activity to use settings