[tcp_server] clean-up.
[setting*] std bind based callbacks implementation.
[spi] std bind based callbacks implementation. std thread based transmission.
Bitmap drawing tools added.
bitmap compilation fix.
[spi] thread management improvement
[mode_image_picker] first implementation.
Application version and mode UDP port added to JSON.
version set to 0.0.4 for release.
[spi] reversed to old threading style.