[autobisectjs] Switch to using standalone autobisect project for date-based bisection

[nth10sd]

Online autoBisect uses builds from archive.mozilla.org, but when the latter does not update its builds, it is hard to find recent builds to download easily. e.g. at:
https://archive.mozilla.org/pub/firefox/tinderbox-builds/mozilla-inbound-linux64-debug/

The most recent builds are from mid-May 2016. Mac builds don't seem to be affected, nor Linux 32-bit ones.

We might want to add support for bisecting using dates from archive.mozilla.org.

[nth10sd]

archive.mozilla.org seems likely to be replaced by taskcluster builds eventually, so we should move to using the standalone Autobisect project instead.