Linux: fix handling of zombie processes
no need to manually set the display resolution anymore
CDisplaySettings: improve screen options filler to determine the current screen
settings: make sure videoscreen.screen/resolution change if videoscreen.screenmode is changed
settings: add OnSettingPropertyChanged callback to ISettingCallback
settings: add IsEnabled() to CSetting
settings: move dependency logic from CGUIWindowSettingsCategory to CSettingsManager
CDisplaySettings: don't show a prompt when switching from/to windowed mode
remove unused methods from CSettings
pvr: fix channel switch for addons using other stream
settings: move <dependencies> tag out of <control> tag
settings.xml: remove unneeded <control> tags for action settings
settings: move <allowempty> tag into <constraints> tag
settings: move <addontype> tag into <constraints> tag
settings: move <heading> tag into <control> tag
settings: move <formatlabel> tag into <control> tag
settings: use #define for XML tag parsing
Merge pull request #2763 from Montellese/settings_definition_cleanup

settings: cleanup of the XML definition syntax
[language] add UI setting descriptions
Merge pull request #2717 from MartijnKaijser/settings_info

[language] add GUI setting descriptions