app-bundled.js etc not generated in windows

When running in windows the app-bundled.js and inline-bundled.js are not generated. If I go to the the docpad.coffee file and add `.cmd` on the end of the `#{rootPath}/node_modules/.bin/browserify` line then the problem is solved. Similar to issue #478 in docpad: https://github.com/bevry/docpad/issues/478

Accidently posted at  docpad/gui issue #29: https://github.com/docpad/gui/issues/29
