Add show_char and show_message

[Ellipse0934]

Added 5x8 pixel font, show_char() and show_message() functions, removed sticktask(). Removed deprecations from LED module

[Ellipse0934]

1) Any name changes for show_char() and show_message() ?

2) I removed deprecations based on their warning messages. I haven't investigated beyond that.

3) Removed sticktask() because produce() was deprecated and the same effect can be achieved by doing something like:

c = Channel{StickEvent}(32)
@async while true put!(c, readstick()) end

@aviks , @simonbyrne

[simonbyrne]

Thanks!