Androind build -900

[Dirk Hohndel]

Apparently I forgot to post about this yesterday. How odd.

Anyway, I implemented Thomas' idea of a timed undo dialog for the delete
action. Please give it some testing. I tried all the scenarios I could
think of (including deleting the last dive in a trip and then undoing that
delete). The undo stack has depth ONE, so only the last delete can be
undone and only within 3 seconds of doing so - basically if you do
nothing, the app does what you told it to do; it deletes the dive. And the
UI isn't blocked by the option to undo, you can just keep going.

I like this user interaction (great work, Thomas), but I want to make sure
I didn't miss anything in the way I implemented it.

/D