replacing File>Open Folder implementation of SHBrowseForFolder() with IFileDialog+FOS_PICFOLDERS
adding comments and flag to prevent from adding chosen folder to MRU
toggle between old and new file dialog based on current OS
Merge remote-tracking branch 'origin/master' into bchin/open-folder-using-IFileDialog
Merge pull request #247 from adobe/bchin/open-folder-using-IFileDialog

Update "File > Open Folder..." dialog with Windows' Open File dialog in pick folders mode.