Create drop-down for Resurvey Validation key-value pairs and include checkbox

[aarewhyan]

Fixes #1101. Continuation of pr #2251.

Uses a map on checkbox updates so as to not query the database on every checkbox click.

Two questions here -

1. It doesn't seem to me to be a good-first issue as I had to deal with cursor deadlocks and memory leaks for updating the header checkbox (but that's beside the point). I was able to fix the former but the latter issue still persists. All I could circle out was, when invoking resetValidator() after the checkbox update to db, the getDefaultValidator(c).reset(c) method makes the app ANR (Reson- Changing to new focus Window timeout), some threading issue I guess, and if I run the program without the reset then, no problem while the app is open but when the app is closed and a new instance is opened, it crashes the app again for the same reason. Meaning there is a conflict with the updated values and the old values that were never rest. This only happens when resetValidator() is called for the checkbox update and not for any other calling of resetValidator() (like adding a ruleset or updating it).

2. I would ask you to point me on how to invoke the following page directly, for testing the resurvey validators. All I could figure out was that as this page is part of the PerfEditorFragment, it can only be invoked when a preferenceScreen is created which itself is created by PerfEditor & PerfEditorActivity. What I can't figure out is how is this created. If you could point me to a simple initialization of this page that would be helpful.
   

[aarewhyan]

@simonpoole can you give some review on the above questions related to the pull request....?

[simonpoole]

@simonpoole can you give some review on the above questions related to the pull request....?

I'm away till the end of next week and will give it a look then.