Dropped MANUAL sort

[kdcro101]

@leftstick ,

In this PR i have removed MANUAL sort altogether.

Why?

If you sort root nodes as MANUAL what will you do with child/descendant items? What sort direction? You can't sort descendants as manual because you would have to:

• add functionality to move up/down every file and directory
• store ordering (what about newly created files or/and directories?) per node (directory)
• assume sort ordering for non-stored nodes (again ASC or DESC)

If you drop MANUAL everything gets in predictable order : ASC or DESC.

[leftstick]

First, I am really appreciated for your contribution. But i 'm sorry i cannot merge your code. Here are some tips for you:

1. one thing for one PR, too many updates in one PR is not friendly to repo owner
2. never format code in a different way while it's not your target
3. remove feature is not an easy story, you don't know how many developers working rely on it. Even it is not perfectly implemented