Enforce Coding Standard: Block Comment.

Several commits early in the repository history started subtle deviations
from the coding standards specifications on block comments.  This commit
is a purely non-functional change, as it only changes comment styling.  To
clarify the desired style:
  -JavaDoc style comments should only be found in C files.
  -Header files should have simple paragraph style descriptions.
    These are intended as an introduction to the interface exposed
    by the .h file.