Document new protocol versions in wireprotocol

[mrotteveel]

Currently, wireprotocol documents version 10, and some parts of version 11 and 16 (batches).

[einar-hjortdal]

I am stuck at parsing protocol 18 row data. this chapter of the documentation doesn't help 😿

[mrotteveel]

Yes, that section still needs to be written :/

The problem seems to be that you calculate the wrong length for the null bitset, which results in an off-by-4 error in reading the response (depending on the number of columns you're selecting):

Specifically:

if xsqlda.vars.len % 8 == 0 {

should be

if xsqlda.vars.len % 8 != 0 {

Though I would actually recommend to remove that if and instead use

mut n := (i32(xsqlda.vars.len) + 7) / 8