settings: add SetLabel() and SetHelp() to CSetting, CSettingCategory and CSettingSection
settings: add a "Reset above settings to default" control at the end of every settings list
[confluence] settings: get rid of the sidebar
settings: show a dummy category if no categories are available for the current setting level (fixes #14649)
Merge pull request #3498 from Montellese/settings_skin_integration

Improved settings level integration into confluence