Added page revision counting

Adds stored revision counts to pages and the revisions themselves.
Closes #321

database/migrations/2017_04_20_185112_add_revision_counts.php

@@ -0,0 +1,44 @@
+<?php
+
+use Illuminate\Support\Facades\Schema;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Migrations\Migration;
+
+class AddRevisionCounts extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('pages', function (Blueprint $table) {
+            $table->integer('revision_count');
+        });
+        Schema::table('page_revisions', function (Blueprint $table) {
+            $table->integer('revision_number');
+            $table->index('revision_number');
+        });
+
+        // Update revision count
+        $pTable = DB::getTablePrefix() . 'pages';
+        $rTable = DB::getTablePrefix() . 'page_revisions';
+        DB::statement("UPDATE ${pTable} SET ${pTable}.revision_count=(SELECT count(*) FROM ${rTable} WHERE ${rTable}.page_id=${pTable}.id)");
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('pages', function (Blueprint $table) {
+            $table->dropColumn('revision_count');
+        });
+        Schema::table('page_revisions', function (Blueprint $table) {
+            $table->dropColumn('revision_number');
+        });
+    }
+}