replace GPL diff lib with MIT lib

replace gpl lib with mit lib

app/Http/Controllers/PageController.php

@@ -12,7 +12,7 @@
 use BookStack\Repos\PageRepo;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Views;
-use Icap\HtmlDiff\HtmlDiff;
+use GatherContent\Htmldiff\Htmldiff;
 
 class PageController extends Controller
 {
@@ -334,9 +334,8 @@ public function showRevision($bookSlug, $pageSlug, $revisionId)
         $page = $this->pageRepo->getBySlug($pageSlug, $book->id);
         $revision = $this->pageRepo->getRevisionById($revisionId);
 
-        $next     = $revision->getNext() ?: $page;
-        $htmlDiff = new HtmlDiff($revision->html, $next->html, true);
-        $diff     = $htmlDiff->outputDiff()->toString();
+        $next = $revision->getNext() ?: $page;
+        $diff = (new Htmldiff)->diff($revision->html, $next->html);
 
         $page->fill($revision->toArray());
         $this->setPageTitle('Page Revision For ' . $page->getShortName());

composer.json

@@ -6,6 +6,8 @@
     "type": "project",
     "require": {
         "php": ">=5.5.9",
+        "ext-tidy": "*",
+
         "laravel/framework": "5.2.*",
         "intervention/image": "^2.3",
         "laravel/socialite": "^2.0",
@@ -14,7 +16,7 @@
         "league/flysystem-aws-s3-v3": "^1.0",
         "barryvdh/laravel-dompdf": "0.6.*",
         "predis/predis": "^1.0",
-        "icap/html-diff": "^1.1"
+        "gathercontent/htmldiff": "^0.2.1"
     },
     "require-dev": {
         "fzaninotto/faker": "~1.4",

resources/assets/sass/_pages.scss

@@ -62,15 +62,15 @@
   }
 
   // diffs
-  .diff-html-removed,
-  .diff-html-added {
+  ins,
+  del {
     text-decoration: none;
   }
-  .diff-html-added {
-    background: rgba(45, 255, 0, 0.2);
+  ins {
+    background: #dbffdb;
   }
-  .diff-html-removed {
-    background: rgba(255, 0, 0, 0.2);
+  del {
+    background: #FFECEC;
   }
 }