Enhance file/folder unlocking capability

[wabxn]

One of XnView's better features is the ability to rename active files and folders. However, this capability is limited by locks that other programs enforce. In a common scenario, I might have viewed or edited a picture in Photoshop, at which point attempts to rename the file or parent folder with XnView will not work. This is also the case when I have viewed files or folders with my Explorer replacement. Either of these programs will block XnView's renaming process until they are closed. If XnView had a global unlocking feature, considerable time could be saved while reducing the likelihood of error due to deferred renaming.