Emit 3rd value

This is kind of ugly, but there are perf implications to slicing on
arguments and it isn’t necessary here
Do not emit EPERM if ignorePermissionErrors

Resolves gh-183
Resolves gh-184
Set default for persistent option to true

gh-181
Merge branch 'master' into vimsafe

* master:
  Set default for persistent option to true
  Do not emit EPERM if ignorePermissionErrors
  Emit 3rd value

Conflicts:
	index.js