[Bug 429916] rename is broken on Node server
* Node file API should not put 'ChildrenLocation' property on regular files
* extensionCommands should check for bad replacement value, not throw.
* commandRegistry._render() should not terminate if command.visibleWhen() throws.
Bump node to v0.0.26 to pick up fix for Rename bug
https://bugs.eclipse.org/bugs/show_bug.cgi?id=429916
Update Node readme to 6.0
Slim down published Node repo
Bump node version to v0.0.27