naughty list should not incriminate the user

[monicachew]

We probably shouldn't expose the list of sites that user wants to keep private in the code itself, especially if we are going to do things like "remember sites that users open in PB mode and add them to the list".

Instead, we should probably do something like keep hashes of URLs on the list, so that if someone finds the list it'll be marginally more difficult to see that the user wants to keep pokerstars or whatever in PB mode.

[monicachew]

Obviously this breaks the substring matching that you're using to check to see if new URLs should be opened in PB mode, since hashes don't preserve substrings.

[monicachew]

Moved to mozilla/blushproof.