fix gulpfile on Windows when the working directory contains spaces
fix Windows path issues and static-file copying (#785)

- In the default template, look for the list of static file paths in the
config property `templates.default.staticFiles.include`. (You can still
use `paths` instead of `include`.)
- Handle path-normalization issues that prevented the default template
from copying user-specified static files on Windows.
- Normalize paths in `fs.toDir` so that callers get the correct path
separator on Windows.