* Add javascript.options.weakrefs and plumb it through context options, XPConnect, and workers
* Keep referents alive via strong tracing when the pref is off so deref() still returns the target
* Retain weak-edge semantics when the pref is enabled
From the spec: "If nesting level is greater than 5, and timeout is less than 4, then set timeout to 4.",
therefore not having it user-configurable doesn't really break anything.
Since these are just interpreted comments, there's 0 impact on actual code.
This removes all lines that match /* vim: set(.*)tw=80: */ with S&R -- there are
a few others scattered around which will be removed manually in a second part.
