OpenSolaris apparently doesn't have timeradd(), so we added a
replacement, but we weren't including it here after the big
refactoring in 0.3.5.1-alpha.
Fixes bug 27963; bugfix on 0.3.5.1-alpha.
Fun fact: these files used to be called log.[ch] until we ran into
conflicts with systems having a log.h file. But now that we always
include "lib/log/log.h", we should be fine.