protocol/nefarious: add Nefarious 2 SASL support
protocol/nefarious: send the account timestamp in svslogin
Merge pull request #248 from grawity/nefarious2-sasl

protocol/nefarious: add Nefarious 2 SASL support
buildsys: check for libqrencode
Pass the entire myuser_t* to svslogin_sts()

Some protocol modules, like nefarious, want to access other fields than
just `->name`; this avoids having to call myuser_find() just to find the
same myuser that's already known. (Ref: #248)

It does, however, change the protocol module API.
libathemecore: add qrcode API
Merge pull request #249 from grawity/svslogin-myuser_t

Pass the entire myuser_t* to svslogin_sts()
Merge pull request #250 from kaniini/master

Add API for rendering QR codes