Log `willSample` prepublish replacer

[rf]

This requires an updated larch so it isn't ready to land yet, but it works.

Wrote a simple script to insert willSample checks before log lines. I messed around with using some macro systems (sweet.js and the C preprocessor) but found that neither would work. The replacer script is an inelegant solution but it's short and it works.

r: @raynos @jcorbin

[Raynos]

This seems reasonable.

I want to try running it and looking at a diff of the pre-process vs post-process.

Also we need to figure out what to do in terms of workflow, prepublish might have to copy into a "build/*" folder and we should change the package.json to import from there.

Then we can .gitignore build/*

[Raynos]

tests fail lal.

[rf]

Changed this to use publish.sh. It's real ugly but it runs the replacer, makes a temp commit, creates the package, then resets git.

[Raynos]

we need to fix debug logtron.