Update to version 0.9.4+git20181129.a7ec3e6: * Add new BGRT theme, using the firmware boot splash as background * two-step: bgrt: Deal with quirky firmwares, Add ACPI BGRT extension support, Speed up background-tile drawing on HiDPI screens, Use a pixel-buffer instead of an image for the view's background * ply-pixel-buffer: Add ply_pixel_buffer_rotate_upright helper, Add ply_pixel_buffer_get/set_device_rotation helpers, Fix marking buffers as opaque when doing a solid fill, Fix fill_with_buffer fastpath when device_scale != 1.