ui: More mis-alignments and strange buttons on plugin add

include/staff/apikey.inc.php

@@ -114,7 +114,7 @@ $info=Format::htmlchars(($errors && $_POST)?$_POST:$info);
         </tr>
     </tbody>
 </table>
-<p style="padding-left:225px;">
+<p style="text-align:center">
     <input type="submit" name="submit" value="<?php echo $submit_text; ?>">
     <input type="reset"  name="reset"  value="<?php echo __('Reset');?>">
     <input type="button" name="cancel" value="<?php echo __('Cancel');?>" onclick='window.location.href="apikeys.php"'>

include/staff/page.inc.php

@@ -190,7 +190,7 @@ else
         </tr>
     </tbody>
 </table>
-<p style="padding-left:225px;">
+<p style="text-align:center">
     <input type="submit" name="submit" value="<?php echo $submit_text; ?>">
     <input type="reset"  name="reset"  value="<?php echo __('Reset'); ?>">
     <input type="button" name="cancel" value="<?php echo __('Cancel'); ?>" onclick='window.location.href="pages.php"'>

include/staff/plugin-add.inc.php

@@ -17,7 +17,7 @@ foreach ($ost->plugins->allInfos() as $info) {
     if (isset($installed[$info['install_path']]))
         continue;
     ?>
-        <tr><td><button type="submit" name="install_path"
+        <tr><td><button class="button action-button" type="submit" name="install_path"
             value="<?php echo $info['install_path'];
             ?>"><?php echo __('Install'); ?></button></td>
         <td>