Fix mac implementation of showOSFolder() to show the open folder instead of the folder within the parent. This commit keeps the current functionality for files, where the parent folder is opened and the file is selected.
Merge branch 'master' into new-open-in-os
Upgrade Win version of ShowFolderInOSWindow() to support passing a file
too - opening the parent folder with that file already selected. (The Mac
counterpart of this is already done in 1a3b149).
Merge pull request #244 from adobe/new-open-in-os

APIs to open a folder with file pre-selected