Tighten regex for pulling sysctls.

Anchor the regex at the start of the line
otherwise ANY line that sort of looks like a
numeric sysctl will be pulled in.

Case in point, we were seeing this slip into our
data files:
  <118> syncpeer: 0.0.0.0 maxupd: 128
because it matched the regex.
Script to fixup bad sysctl log files.

Our previous scraper was getting bad data from
sysctl.  This script fixes it.

Basically clear out anything like:
  "<118> syncpeer: 0.0.0.0 maxupd: 128"
Allow to be run with filename args.
Cleanup sysctl regex to get nodes with numbers.

The previous regex would only allow sysctl nodes
with zeros, but not any other digit.  Fix the regex
to grab those as well.
Cleanup other regex leaks from previous versions.

The weak regex allowed some sysctls in the form of
"foo: bar: 33" which was causing the transform.py
to blow up.  Destroy these as well.
Show what broke parsing if we get an exception.