multithreaded download and files that probably should have been in the last

commit

For testing the new iteration, the texture cache disk download was written
into the main thread instead of into the separate threads. Now they're back
in separate threads again.

Also I think some of these files probably should have been in the previous
commit.

app/node/input/media/video/video.cpp

@@ -58,13 +58,13 @@ QString VideoInput::Code(NodeOutput *output)
   if (output == texture_output()) {
     return "#version 110\n"
            "\n"
-           "varying vec2 olive_tex_coord;\n"
+           "varying vec2 v_texcoord;\n"
            "\n"
            "uniform sampler2D footage_in;\n"
            "uniform mat4 matrix_in;\n"
            "\n"
            "void main(void) {\n"
-           "  gl_FragColor = texture2D(footage_in, vec2(vec4(olive_tex_coord, 0.0, 1.0) * matrix_in));\n"
+           "  gl_FragColor = texture2D(footage_in, vec2(vec4(v_texcoord, 0.0, 1.0) * matrix_in));\n"
            "}\n";
   }