Upgrade to iOS 5 features; Enable background GPS updates; remove custom lock slider code in favor of native iOS lock.
Add cancel button image resource that was omitted from previous commit.
Update Copyright and Contact info
Merge remote-tracking branch 'pschmied/master'

Updating to the background work done by pschmied (Thanks, Peter!)
Remove unused code, use local notifications

Remove unused code, use local notifications instead of a timer since it
reminders make sense in background mode.  Move battery check out (it
will go into the RecordTripController).
Fix typo, add unloadTrip method for cancelling
Deprecate more unused code; added background/foreground logic and battery checking.
Update button sizes
Deprecate unused lock buttons
AFAIK no real changes here
Button updates (start button = save button; cancel button is hidden)
Update version for release 2.1 (was 2.0.1).  Update for retina icons.
Deprecating some more unused images
.gitignore + project files update
Remove pid from localnotif alert
No change
Fix for iphone retina 4-inch.  Stretch button images to appropriate width.
Use modified help URL
Update trip purpose images for retina (convert to png)
Add tab bar retina images