Multiple globs in one site configuration

Would be a big win for readability if multiple `GlobObject` specs were allowed on a `siteConfig`.
E.g.

```
"sites": {
"docs": {
"parent" : "root",
"dest" : "./out",
"glob" : [{
"pattern" : "docs/**/*.md"
}, {
"cwd" : "../Scripts/some-namespace",
"pattern" : "{cherry,picked,files}.js"
}, {
"cwd" : "../Scripts/some-other-namespace",
"pattern" : "**/*.js",
"ignore" : "{ignore,only,these,files}.js"
}]
}
}
```

Having to roll that up into one glob leads to an unreadable, unmaintainable mess.

Start by locating the siteConfig and GlobObject definitions and the existing glob-processing entry point. Compare how one glob is currently parsed with the issue's array example. Done means a site configuration accepts multiple GlobObject specs, including separate cwd, pattern, and ignore values, while preserving existing single-glob behavior.

Written by the indexing model from the issue text.