refs #9231 Make all log_* tables fields NULLable (#10492)

core/Db/Schema/Mysql.php

core/Updates/3.0.0-b1.php

plugins/Actions/Columns/EntryPageTitle.php

plugins/Actions/Columns/EntryPageUrl.php

plugins/Actions/Columns/ExitPageTitle.php

plugins/Actions/Columns/TimeSpentRefAction.php

plugins/Actions/Columns/VisitTotalActions.php

plugins/Actions/Columns/VisitTotalSearches.php

plugins/CoreHome/Columns/VisitGoalBuyer.php

plugins/CoreHome/Columns/VisitGoalConverted.php

plugins/CoreHome/Columns/VisitorDaysSinceFirst.php

plugins/CoreHome/Columns/VisitorDaysSinceOrder.php

plugins/CoreHome/Columns/VisitorReturning.php

plugins/DevicePlugins/Columns/PluginCookie.php

plugins/DevicePlugins/Columns/PluginDirector.php

plugins/DevicePlugins/Columns/PluginFlash.php

plugins/DevicePlugins/Columns/PluginGears.php

plugins/DevicePlugins/Columns/PluginJava.php

plugins/DevicePlugins/Columns/PluginPdf.php

plugins/DevicePlugins/Columns/PluginQuickTime.php