Update port.rs to do \r\n

[rsahwe]

rust uses only \n regardless of platform and some serial monitors such as the qemu one need \r\n. This would fix this.

[phil-opp]

Thanks for the PR! Seems reasonable to me.

Could you document in the method docs that send does this replacement and link to send_raw as alternative?

I just noticed that we also do some replacements for 8 | 0x7F bytes. I don't remember why we did this, perhaps you have an idea? Either way, we should document this replacement too.

[rsahwe]

8 is backspace and the replacement explicitly overwrites the character with space, probably because sometimes backspace only moves the cursor. I don't know why 0x7f (delete) also does backspace though.

[phil-opp]

Thanks!

I don't know why 0x7f (delete) also does backspace though.

Seems a bit weird to me too. What do you think? Should we remove that replacement?

[rsahwe]

I don't know, this has apparently always been a part of the crate and this might be some weird uart thing where delete does not exist. Maybe ask the person who wrote that part.

[phil-opp]

Published as v0.4.0.