Remove passwords reflection from logging messages

  Implement custom Logger class for sanitizing dict(), list() and
  fuel_upgrade.config.Config() instances.
  Add sanitizer() function which substitutes config data with mask
  based on keywords.
  Refactor all logger calls to use the sanitizer.

Closes-Bug: 1387164
Change-Id: I810610aed59f7a6a904b1bcfe4d89b674aba96fc
Merge "Remove passwords reflection from logging messages"