Move CardOS 5 specific functionality

Move CardOS 5 specific functionality from iso7816.c (which is card-independent)
back to card-cardos5.c, as pointed out by dengert@.
Remove two unused variables.
Add cardos5.profile, based on cardos.profile.

XXX As it is, cardos5.profile is merely a slightly trimmed version of
cardos.profile. This needs adjustment.
Provide CardOS 5 with a working logout callback.

This callback issues a RESET SECURITY STATUS command. Is there a reason why this
callback isn't implemented for CardOS 4.4, which supports the same command?