Code audit and cleanup for GC (WOCommon, c176086)

This is the other part of the GC audit. The number of lines changes here (nearly 400 insertions, 1000 deletions) is not as much as was the case in the Synergy codebase as the WOCommon code is more "modern" and there was less to do, but it's still a significant change.

Signed-off-by: Greg Hurrell <greg@hurrell.net>