[aur-general] Removal request

[Nicola Bignami]

icecat-ka --- Orphan, outdated, no longer available upstream.
https://aur.archlinux.org/packages.php?ID=38420

icecat-oc --- Orphan, outdated, no longer available upstream.
https://aur.archlinux.org/packages.php?ID=38433

savekernel --- Orphan, outdated, no longer available upstream.
https://aur.archlinux.org/packages.php?ID=15004

skulltag-x86_64  --- Orphan, replaced by skulltag package that now 
supports also 64bit.
https://aur.archlinux.org/packages.php?ID=40360