From Ken's draft:
authorArnt Gulbrandsen <arnt@oryx.com>
Wed, 30 Jan 2008 15:03:22 +0000 (15:03 +0000)
committerArnt Gulbrandsen <arnt@oryx.com>
Wed, 30 Jan 2008 15:03:22 +0000 (15:03 +0000)
commit8a5608ccb04ad7e08d5553dc3d0afec675e9d294
tree020dc6e2df2d6086d0664d932061a45d1a9ffedc
parent38d4531cacebbd6ae362d097b6f826fca0306573
From Ken's draft:

    Note: There is at least one widely deployed client which
    requires that the challenge strings transmitted by the
    server be "Username:" and "Password:" respectively.  For
    this reason, server implementations MAY send these
    challenge strings instead of those listed above.

So that's what we do.

p4raw-id: //oryx/src/main@54875
imap/handlers/select.cpp
sasl/sasllogin.cpp