I moved the wasm update scripts from tools/ to tools/wasm. In addition
I cleaned up the scripts a bit.

R=machenbach@chromium.org

Change-Id: I545dd556712e272e6509b78e343e9063346abe56
Reviewed-on: https://chromium-review.googlesource.com/488601Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44940}