fix Node.js postinstall script on Windows

should now work on Windows XP and in shells without admin privileges
comment out hashbangs in files with Windows line endings
on Rhino, optimize the order of the module paths

resolves a Windows issue that caused modules to be discovered in the
wrong order
whitespace
updated Rhino that can load modules from a path

thanks to this change, we can rip out some code that converts paths to
URIs and vice-versa.

https://github.com/jsdoc3/rhino/0f7750b1
fix various path-related issues on Windows

- add env.pwd global, and use it instead of process.env.PWD, which is
undefined in Node.js on Windows
- normalize paths where necessary