v0.6

c69a43b release
88a7769 fix windows cross builds
4f09707 update the todo list
4b6cd31 fix th_canvas_line
6cdaf90 fix conv_path
c98b891 replace rawdraw with own functions
2c46a7f normalize vertices in image drawing
ad6da6d own compile shader functions
7bbac0a switch to ^font.Cached in ui.Label
52176b7 add color filter to images