Onscreen IDE & dynamic instant update [_v0.5.4_]

UPDATES :
[X] fixed EoL deletion redo bug
[X] fixed document’s changed status upon indentation undo/redo
[X] added join lines ability
[X] now you can change files tabs order, drag it with LMB
[X] removed wx modal dialog usage, so I don’t have to use multiple threads at all.
It’s replaced by my own dialog & polygonal buttons module :

Thus, it also minimizes the annoying window switch when going fullscreen on Windows.

Note : it’s still using python only task[Mgr]