These packages are based on slackware-current binaries.
slackware_base and its dependencies need some non-standard stuff (in terms
of wip/mk/linuxbin.pkg.mk) to install - basically, they handle their
installation stuff on their own.
slackware_gcc and slackware_tcsh are included as an example "extra" packages
for Slackware base - they are not needed for basic functionality, but as
bin/cp, bin/sh and other utilities are installed by the time slackware_tcsh
or slackware_gcc is installed, they can handle their installation only via
wip/mk/linuxbin.pkg.mk and nothing else
