Add Password Prompt
Merge branch 'password_prompt' of git://github.com/ElPincheTopo/liner
Remove pointless columns check in PasswordPrompt

The fast-path "avoid full refresh" was copied from the main loop. It is
not a fast path in reverseISearch because PasswordPrompt always has to
do a full refresh.

Simplify the code slightly by removing the unnecessary if{} block.