Set parent for options dialog where appropriate.

Otherwise the options dialog might appear behind the current "dialog"
(for example the "new" wizards).
Also, take ICore::dialogParent as default.

Change-Id: I4578e269db5763842a942549a45ec8cdd6b28b5d
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/projectexplorer/projectwizardpage.cpp

@@ -215,5 +215,6 @@ void ProjectWizardPage::slotProjectChanged(int index)
 void ProjectWizardPage::slotManageVcs()
 {
     Core::ICore::showOptionsDialog(VcsBase::Constants::VCS_SETTINGS_CATEGORY,
-                                   VcsBase::Constants::VCS_COMMON_SETTINGS_ID);
+                                   VcsBase::Constants::VCS_COMMON_SETTINGS_ID,
+                                   this);
 }