Fix issue with non-unique ID in markup and adjust tab location (fixes #43)

Author: teppokoivula

VersionControl.module

@@ -29,7 +29,7 @@ class VersionControl extends WireData implements Module, ConfigurableModule {
             'summary' => 'Version control features for page content.',
             'href' => 'https://modules.processwire.com/modules/version-control/',
             'author' => 'Teppo Koivula',
-            'version' => '1.3.4',
+            'version' => '1.3.5',
             'singular' => true,
             'autoload' => true,
             'installs' => array(
@@ -1054,6 +1054,7 @@ class VersionControl extends WireData implements Module, ConfigurableModule {
             $wrapper->prepend($fieldset);
 
             $field = $this->modules->get("InputfieldHidden");
+            $field->id = 'history_filters__id';
             $field->name = 'id';
             $field->value = $page->id;
             $fieldset->add($field);
@@ -1077,11 +1078,15 @@ class VersionControl extends WireData implements Module, ConfigurableModule {
         $this->config->scripts->add($this->config->urls->$class . "HistoryTab.min.js?v=$version"); 
 
         // insert new tab to Page Edit form
-        $form->append($wrapper);
+        $submit = $form->find('name=submit_save')->first();
+        if ($submit) {
+            $form->insertBefore($wrapper, $submit);
+        } else {
+            $form->append($wrapper);
+        }
         if (!method_exists($event->object, "getTabs")) {
             // note: this works for ProcessWire < 2.4.18 and won't be reached
             // after 2.5.14 at all; see addTabHistory() for more details.
-            $form->append($wrapper);
             $siblings = $form->children('id=ProcessPageEditSettings|ProcessPageEditDelete|ProcessPageEditView');
             if (count($siblings)) {
                 if ($siblings->first()->attr('id') == "ProcessPageEditSettings") {
@@ -1116,10 +1121,8 @@ class VersionControl extends WireData implements Module, ConfigurableModule {
         $keys = array_keys($event->return);
         if (($pos = array_search('ProcessPageEditSettings', $keys)) !== false) {
             $pos += 1;
-        } else {
-            if (($pos = array_search('ProcessPageEditDelete', $keys)) === false) {;
-                $pos = array_search('ProcessPageEditView', $keys);
-            }
+        } else if (($pos = array_search('ProcessPageEditDelete', $keys)) === false) {
+            $pos = array_search('ProcessPageEditView', $keys);
         }
         if ($pos !== false) {
             $event->return = array_merge(