improved Makefile + small fixes

xattr: tolerate ENOTSUP (behave like there are no attributes when not supported on given FS)

Added tag v0.1 for changeset 22827574296e

reset texture scale back to 1:1, if xattr is missing

new default texture: horizon

add Texture::bind() method

pass texture xattr 'shader-shark.texture.scale' to the shaders as 'uTextureScale' + update variable locations on each shader reload

xattr: list attribute names without the namespace prefix 'user.'

support both decimal and hexadecimal notations for --root-window

set scaling filters according to the texture file extended attributes (xattr: shader-shark.texture.mag-filter = linear | nearest)

xattr: XAttrs class that read/write/list extended attributes

monitor texture and shader file writes using inotify: improved resource management

texture magnification filter: linear (blurry) vs. nearest (sharp/pixelatex)

shaders: dynamic line count derived from the texture resolution

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

support custom shaders

OOP for Shader and ShaderProgram