Added Plugin support (#102)

* Build refactoring and initial plugin support

* Possibly fixed linux / mac build

* Added libdl to libglad build script

* Add glfw to imgui dependencies

* Refactored common functionality into "libimhex" for plugins

* Added plugin loading and example plugin

* Added proper API for creating a custom view and a custom tools entry with plugins

source/views/view_bookmarks.cpp

@@ -39,7 +39,7 @@ namespace hex {
         View::unsubscribeEvent(Events::ProjectFileStore);
     }
 
-    void ViewBookmarks::createView() {
+    void ViewBookmarks::drawContent() {
         if (ImGui::Begin("Bookmarks", &this->getWindowOpenState())) {
             if (ImGui::BeginChild("##scrolling")) {
 
@@ -107,7 +107,7 @@ namespace hex {
         ImGui::End();
     }
 
-    void ViewBookmarks::createMenu() {
+    void ViewBookmarks::drawMenu() {
 
     }