  o Code simplifications and unit tests:
    - 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.
    - Consistently check for overflow in round_*_to_next_multiple_of
      functions, and add unit tests with additional and maximal values.

