Various code clean-ups.

Various code clean-ups.

* Combine definitions with initialization.  This had to be foregone in
  two instances where that would have otherwise caused an unused variable
  warning.

* Move the HS_BOILERPLATE macro to the top of the calling function.  This
  macro checks that certain globals are initialized.  It should be removed
  after the callers become members functions of a class.

* A few cases of inconsistent function declaration styles have been brought
  in line with the rest of the file.  These were overlooked in a previous
  clean-up.

* The unused heap source debugging macros and tracing code have been
  removed.

* One stale comments has been removed and another has been updated.

Change-Id: I20bf4b78161096310b79d7dd294d7636e6bb6f48