don't set fixed width for "Line" section
don't set fixed width for icon column of keybindings table
use splitter in settings dialog
change layout of elements on EditorSettingsPage to save horizontal space
use new capabilities of QLineEdit in DocListPanel
use icons from theme in fm's panel if they are available
avoid setting fixed width for widgets in status bar
Merge pull request #64 from volkov0aa/high-dpi-support

High DPI support