[x] predefined number for distress call
[x] main activity should stop service if settings changed
[x] "don't show again" messages reset
[-] when to reset distress dynamo? : just rotating dynamo infinitely
[x] indicate location sent
[x] backup/restore
[x] delete bookmark confirmation
[x] cancel distress call in UI
[x] MainActivity need refactoring
[ ] bring apk under 64k
