#1642 7ZFM improvements suggestion

[Ihar Areshchankau]

Hello!
Let me suggest a few improvements to the 7Zip File Manager (7ZFM) behaviour.

1) Always keep any element selected on the panels.
Let's say we deleted or moved a file. After that, none of the files in the Source panel will be selected, but a dotted border around some file will be displayed. If we select some operation (Copy, Move or Delete), it will be applied to the entire contents of the panel (files and folders).

2) Don't perform any actions with files that contains dots only ("." and "..").
If we select any operation (Copy, Move or Delete) for these files, the action will be applied to the entire contents of the panel.

Thank you!