implement draging files to desktop directly
add ordered queue without order algorithm
implement the heap-sort as the sort algorithm of ordered queue
implement adjusting tabindex of dentries automaticly; implement draging other type of entries into a DirEntry
Merge branch 'dentry3'
Merge pull request #24 from CannedFish/master

Function added: drag file to desktop; auto reorder tabindex; drag other type of entries to DirEntry -->Tanking-1988