There's no way to actually know if those clients have gone away, so it
seems it might be better to base it on whether the user has connected
again with new clients to determine if the old clients are now invalid.

This is so we can try out the web worker extension host.

For example some code tries to run -e against the binary but that fails
since we inject our entry file every time the binary is invoked.

Fixes #932.

Fixes #889. Previous it would use the cwd. In some cases that's the
path of where the binary is located which is a weird place to open.

Fixes #929.

This means something is misconfigured.

Fixes #641.

It gets the web URL for the file yet uses the file service to load it,
so having a sub-path causes it not to be found on disk (the sub-path
obviously only means anything for the web server and isn't on disk).

To ensure users don't lose their extensions when updating.

This removes the potential for a bad build because the native Node
modules currently can only be built on the target system, so specifying
a target for something other than the system your are building on will
not work.

Fixes #898.

Fixes #911.

Fixes #909.

Fixes #901.

This allows piping to things like `head` without SIGPIPE errors.