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.

It's no longer included by the remote dependencies.