Since it's impossible to use std::io::Cursor<T> in a no_std environment I decided to create a very very simple implementation that supports byteorder out of the box since that's how I always use Cursor.
A normal cursor can be found in nostd_cursor::cursor::Cursor
Either use nostd_cursor::LECursor<T> or nostd_cursor::BECursor<T>.
At this point I've only trivially implemented Cursor::read_exact(). If you need anything else that is implemented in the std-version feel free to create a pull request! I'm only planning to add more features when I need them for my personal projects.