* Fix "Install" menu item function

* Remove "Install From Entry" and "Install From File" menu item functions.
  They are useless when a search bar is available.

* Rename some UI objects
* Fix Turkish

* Rewrite "Install From Entry" menu item function

* Rewrite installwindow.py (1/X)
* Add a FIXME to mainwindow.py
* Fix (?) a warning when main window is closed

* Refactor mainwindow.py and infowindow.py (2/X)
* Fix "Info" menu item function

* Rename/refactor mainwindow.py methods (3/X)

* Rename/refactor mainwindow.py methods (2/X)

* Rename/refactor mainwindow.py methods

* Divide menu to two separate menu
* Fix actions (1/X)

The feature is for real names and names.

* Add files from flatpak-gui-old