major set of fixes/tweaks for the frontend following a user test:
major set of fixes/tweaks for the frontend following a user test:

- drag&drop was b0rked, both functionally and visually. When CONTROL key is pressed before starting a drag or when keeping it depressed while drag&dropping multiple files, none or only the first file would be copied, the others moved. This was due to the related keyboard handlers being in- and de-installed with every drag operation. The fix here is to keep these keyboard handlers active all the time and only allow the visual feedback (the fading in green (+) icon) when a drag is happening.

- keyboard handling was a mess. Now multiple keyboard handlers have been merged into a single one.

- revert-->replayClick was more hasssle than it was worth, so this old hack has been removed. Of course, that measn you'll get a 'click' event (replayClick!) immediately following each drag&drop operation (click after drop), but this is neatly handled by stretching the zone where drop_pending != 0: by having the click handler reset the drop_pending to zero on first encounter and otherwise making sure the click handler is not invoked too early, this works well, also when using a combined keyboard/mouse way of navigating the FM.

- see previous point: revert would also 'select' the dragged file, which is plain wrong when it is dropped into another directory and a nuisance when it is copied locally or to another directory: drag&drop 'management activity' is now separate from the 'file selection'.

- several more fixes, e.g. correcting the lacking update of the cached json directory list when a move or delete is completed. This is important when viewing directories in pagination mode: going back & forth should have those moved/deleted items gone _consistently_.

cpojer/mootools-filemanager,cpojer/mootools-filemanager