process all X11 event waiting in the queue in the same cycle avoid so called glitches after continuous key press or X11 tunelled through SSH

OOP for Texture

new shader: phosphor-basic.frag

new shader: scanlines-basic.frag

new shader: soften-borders.frag

transparency/alpha: blending

transparency/alpha: simple binary transparent/opaque, no blending, just discard some fragments

ImageLoader: convert images always to 8-bit depth as expected by Shark.cpp (i.e. 16-bit images can be loaded now)

monitor texture and shader file writes using inotify: reload textures

use default texture and shaders from the $SHADER_SHARK_DATA_DIR directory, if not configured as command line arguments

private Impl class also for the Shark

mouse wheel: move camera, not object

monitor texture and shader file writes using inotify: reload shaders

monitor texture and shader file writes using inotify: print file events