Add SSLSocket#readbyte

[lwoggardner]

Companion to getbyte but raise EOFError
Similar to #438

[rhenium]

Looks good to me. Thank you for your PR!

[lwoggardner]

Thanks @rhenium glad to help.

One question if I may.

My first inclination was to do

getbyte or raise EOFError

ie obvious that there is no way of getting a nil return if somehow EOF occurs between the eof? check and getbyte. This is also seems to be the approach used in the MRI C code for IO::readbyte.

But then I saw all the existing methods used this form...

raise EOFError if eof?
getbyte

I understand that this works because eof? has a side effect of pulling data into the buffer. My question is whether this was a concious choice for performance or some other reason? (and if not would you consider changing it?)