Removed SFTP code

It seems reasonable to hold back preposterous features until we have a
servicable editor.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
Fixed mistakes reported by new compiler

Also added -Werror to the AM_CFLAGS to prevent further warnings from going
unnoticed.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>