Misc (#19)

* get image returns optional<Mat> instead of unique_ptr<Mat>

* introduce complexity

* rename image load function

* add example for a basic reader for binary image files

* fix windows build?

* add a status bar underneath the menu bar

* use status bar in custom_0 example app

* clang formats

* packing w/ pragma push

* add "Save As" functions to image views

* resize over reserve

* rm local override uri

* add simple thread pool

* rename to simple_thread_pool

* get rid of useless renderlib

* document version inc

* extract hardcoded values to in-header

* clang format patch

* clone registered image in custom_0

* document binary-file header

* minor fixes

* clang format

* rm unused render cmake

lib/app/DefaultApp.cpp

@@ -25,7 +25,7 @@ void DefaultApp::MenuBarOptionsColumn2()
     {
         if (ImGui::MenuItem(LOADIMAGE))
         {
-            this->LoadImage();
+            this->LoadImageDialogue();
         }
 
         ImGui::EndMenu();
@@ -40,7 +40,7 @@ void DefaultApp::Run()
     this->gallery_.RenderImages();
 }
 
-void DefaultApp::LoadImage()
+void DefaultApp::LoadImageDialogue()
 {
     auto res{pfd::open_file("Load Inputs", pfd::path::home(), {"All Files", "*"}, pfd::opt::multiselect).result()};
     for (auto& p : res)