Make knownFolders.currentApp default to __dirname.
Make knownFolders.currentApp default to __dirname.

In cases where we can't find a `tns_modules` subfolder (webpack, etc),
assume the current dir is the app dir.

NativeScript/NativeScript,NativeScript/NativeScript,NativeScript/NativeScript,NativeScript/NativeScript,NativeScript/NativeScript