You can search/replace these namespaces in your project after upgrading from 0.8.x to 0.9.x:
de.agilecoders.wicket.markup.html.bootstrap.form.ControlGroup -> de.agilecoders.wicket.core.markup.html.bootstrap.form.FormGroup
de.agilecoders.wicket.markup.html.bootstrap.components.TooltipBehavior -> de.agilecoders.wicket.core.markup.html.bootstrap.components.TooltipBehavior
de.agilecoders.wicket.markup.html.bootstrap.components.TooltipConfig -> de.agilecoders.wicket.core.markup.html.bootstrap.components.TooltipBehavior
de.agilecoders.wicket.markup.html.bootstrap.dialog.Modal -> de.agilecoders.wicket.core.markup.html.bootstrap.dialog.Modal
de.agilecoders.wicket.settings -> de.agilecoders.wicket.core.settings
de.agilecoders.wicket.markup.html.bootstrap.tabs -> de.agilecoders.wicket.core.markup.html.bootstrap.tabs
de.agilecoders.wicket.markup.html.bootstrap.form.BootstrapForm -> de.agilecoders.wicket.core.markup.html.bootstrap.form.BootstrapForm
de.agilecoders.wicket.util.JQuery -> de.agilecoders.wicket.jquery.JQuery
de.agilecoders.wicket.markup.html.bootstrap.button -> de.agilecoders.wicket.core.markup.html.bootstrap.button
de.agilecoders.wicket.markup.html.bootstrap.extensions.form -> de.agilecoders.wicket.extensions.markup.html.bootstrap.form
de.agilecoders.wicket.markup.html.bootstrap.common -> de.agilecoders.wicket.jquery
de.agilecoders.wicket.util.Json -> de.agilecoders.wicket.jquery.util.Json
de.agilecoders.wicket.core.Bootstrap -> de.agilecoders.wicket.Bootstrap