* Add posix handle type shortcut
* Expose device local buffer's memory
* Add exportable memory option for pools & device local memory
* Add test for device local with exportable fd
* Use a convenience function in test
* Dont expose memory, but instead allow export fd directly
* Fix mistakes & clean
* Remove test due to IncompatibleDriver error
* add additional ImageUsage constructors
* update examples to use ImageUsage::color_attachment instead of caps.supported_usage_flags
* fix additional usage in multi-window example
* update ignore to not include mandelbrot.png and triangle.png
* update ignore to not include mandelbrot.png and triangle.png
* replaced `.expect()` that provided no useful information with `.unwrap()`
* used `use` consistently (all types are `use`d all functions have the parent module `use`d)
* other formatting consistencies
