Iffy log screen behavior

[tmplt]

There are multiple smaller issues with the log screen, currently (after 80900e4):

• While detached, moving down from the third entry after a multi-line entry takes to calls to move(down).
• While logs are being fed (test with --debug), move(top) does not work as expected.
• While logs are being fed, detached_at_ seemingly changes after detachment. Seem to only happen with multi-line entries.