Add new option `excludeDir` and allow globbing pattern for `exclude` opt...

Add new option `excludeDir` and allow globbing pattern for `exclude` options.

I has use [grunt-rev](https://github.com/cbas/grunt-rev) task in my production build.
Every time build and the file name are different.
I think `exclude` option can use globbing pattern would be more easy to list excluded files.

New option 'excludeDir' can filter out directory if it is true, and the `src` file listing can more coarse grained.

Above features can refer to `excludeTest` use case in Gruntfile.js.