pacinfo: allow package names without database

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
replace deprecated log callbacks

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
paclog: plug memory leak

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
paclog: rename --installed -> --pkglist

In order to more closely resemble paclog-pkglist from pacman contrib.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>