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/imaging/impl/PixelariumPng.cpp

@@ -16,11 +16,11 @@ pixelarium::imaging::PixelariumPng::PixelariumPng(const std::string& uri)
     this->uri_ = std::filesystem::path(uri);
 }
 
-std::unique_ptr<cv::Mat> pixelarium::imaging::PixelariumPng::TryGetImage()
+std::optional<cv::Mat> pixelarium::imaging::PixelariumPng::TryGetImage()
 {
     try
     {
-        auto img = std::make_unique<cv::Mat>(cv::imread(this->uri_.string()));
+        auto img = cv::Mat(cv::imread(this->uri_.string()));
 
         this->is_empty_ = false;