Allow resubmit=1 in request to choose activities even if they've already
been posted.
More automated SQL generation with fall-through support for resubmit.
Include hidden "resubmit" field in the form results to post.rvt
Allow log_error to be used with arbitrary error text, not just
::errorInfo contents.

Rely solely on the log/nolog logic in site_error, not in log_error.
Allow re-posting same activity to RunKeeper if resubmit is set.
Variable name consistency and log API errors to database when they
occur.