Log Message:
Updated lang/spidermonkey to 1.8.0 rc1 (see below).

No standard changelog provided from upstream, some bits scattered here:

* http://www.mozilla.org/js/spidermonkey/release-notes/JS_170.html
* https://developer.mozilla.org/En/SpiderMonkey/1.8

pkgsrc changes:

* Threading support (and dependency on devel/nspr) is now optional
  (enabled by default). Threaded Spidermonkey may not be desirable
  for e.g. server-side JavaScript usage.
* Unicode strings support optional.
* Rudimental OpenSolaris/Solaris 11 config file provided.

Release Candidate note:

Spidermonkey 1.8.0 RC1 was the last version ever released as
a standalone distribution, and is generally being used by the JavaScript
community nowaways, if needed. In the future, ripping Spidermonkey
out of the Mozilla tarball may be attempted too, to update the package
to 1.9.x.