1. A method of merging a source item in a source file directory with a destination item in a destination file directory, the merge method comprising: determining whether the source item is a file or a subdirectory; if the source item is a file, deleting any conflicting item from the destination file directory, and moving the file from the source file directory to the destination file directory without copying the file; if the source item is a subdirectory having no corresponding destination subdirectory, moving the subdirectory from the source file directory to the destination file directory without copying the subdirectory; and if the source item is a subdirectory having a corresponding destination subdirectory, repeating the merge method for each item of the source subdirectory.