Javascript: Show completion for require("../../")

Allow recursive parent directories,
but don't show ../ everywhere.
Javascript: Fix NullRef on JS string completion

Also tweak cursor movement logic, and fix
crash on use directive completion in first line.
Javascript: Fix single-quoted require() go-to-def

Fixes F12 on require('...').myFunc('...')
Merge pull request #314 from SLaks/node-module-fixes

Javascript: Node Completion Fixes