Implement Plugin Loading.

This commit adds plugin laoding which are then added as sub winows onto the main window.
This commit also adds 2 plugins however more will follow

plugins/WebBrowserPlugin/WebBrowserPlugin.cpp

@@ -0,0 +1,78 @@
+#include "WebBrowserPlugin.h"
+#include <QVBoxLayout>
+#include <QWidget>
+
+QString WebBrowserPlugin::pname()
+{
+    return "Web Browser Plugin";
+}
+
+QString WebBrowserPlugin::pdesc()
+{
+    return "Simple Web Browser Plugin.";
+}
+
+QWidget* WebBrowserPlugin::pcontent()
+{
+    QWidget *test = new QWidget();
+    test->setWindowTitle(tr("Web Browser Plugin"));
+    test->resize(1024, 750);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+
+    view = new QWebEngineView(test);
+    view->setUrl(QUrl("https://rubenwardy.com/minetest_modding_book/en/index.html"));
+    view->resize(1024, 750);
+
+    horizontalGroupBox = new QGroupBox();
+    QHBoxLayout *layout = new QHBoxLayout;
+    back = new QPushButton(tr("Back"));
+            layout->addWidget(back);
+    connect(back, &QPushButton::clicked, this, &WebBrowserPlugin::backpage);
+
+    forward = new QPushButton(tr("Forward"));
+            layout->addWidget(forward);
+    connect(forward, &QPushButton::clicked, this, &WebBrowserPlugin::forwardpage);
+
+    refresh = new QPushButton(tr("Refresh"));
+            layout->addWidget(refresh);
+    connect(refresh, &QPushButton::clicked, this, &WebBrowserPlugin::refreshpage);
+
+    smallEditor = new QLineEdit;
+    layout->addWidget(smallEditor);
+    smallEditor->setText("https://rubenwardy.com/minetest_modding_book/en/index.html");
+
+    go = new QPushButton(tr("Go"));
+            layout->addWidget(go);
+    connect(go, &QPushButton::clicked, this, &WebBrowserPlugin::gotourl);
+
+    horizontalGroupBox->setLayout(layout);
+
+
+    mainLayout->addWidget(horizontalGroupBox);
+    mainLayout->addWidget(view,1);
+    test->setLayout(mainLayout);
+
+    QIcon icon = QIcon(":/images/monkey.png");
+    test->setWindowIcon(icon);
+    return test;
+}
+
+void WebBrowserPlugin::gotourl()
+{
+    view->setUrl(QUrl(smallEditor->text()));
+}
+
+void WebBrowserPlugin::refreshpage()
+{
+    view->reload();
+}
+
+void WebBrowserPlugin::backpage()
+{
+    view->back();
+}
+
+void WebBrowserPlugin::forwardpage()
+{
+    view->forward();
+}