scripted-diff: move settings to common namespace

-BEGIN VERIFY SCRIPT-
sed -i 's/namespace\ util/namespace\ common/g' src/common/settings.cpp src/common/settings.h
sed -i 's/util\:\:GetSetting/common\:\:GetSetting/g' $( git grep -l 'util\:\:GetSetting')
sed -i 's/util\:\:Setting/common\:\:Setting/g' $( git grep -l 'util\:\:Setting')
sed -i 's/util\:\:FindKey/common\:\:FindKey/g' $( git grep -l 'util\:\:FindKey')
sed -i 's/util\:\:ReadSettings/common\:\:ReadSettings/g' $( git grep -l 'util\:\:ReadSettings')
sed -i 's/util\:\:WriteSettings/common\:\:WriteSettings/g' $( git grep -l 'util\:\:WriteSettings')
-END VERIFY SCRIPT-

src/common/settings.cpp

@@ -16,7 +16,7 @@
 #include <utility>
 #include <vector>
 
-namespace util {
+namespace common {
 namespace {
 
 enum class Source {
@@ -258,4 +258,4 @@ size_t SettingsSpan::negated() const
     return 0;
 }
 
-} // namespace util
+} // namespace common