tor/changes/laplace-edge-cases

  o Minor bugfixes (statistics code):
    - Handle edge cases in the laplace functions: avoid division by zero,
      avoid taking the log of zero, and silence clang type conversion
      warnings using round and trunc.  Add unit tests for edge cases with
      maximal values. Fixes part of bug 13192; bugfix on 0.2.6.2-alpha.
    - Consistently check for overflow in round_*_to_next_multiple_of
      functions, and add unit tests with additional and maximal values.
      Fixes part of bug 13192; bugfix on 0.2.2.1-alpha.