Bugzilla Bug 258178

Having a use flag for installing one plaintext file doesn't make sense.

- ebuilds don't handle this consistently (some just use this flag for
doins/newins a script to /etc/logrotate.d, some add app-admin/logrotate
dependency, some install the scripts unconditionally)

- users can use INSTALL_MASK if diskspace is an issue for them (extremely
unlikely), plus the installed scripts have no effect until you install
logrotate anyway, so if you don't want this functionality, just don't install
it, if you do, emerge logrotate and you don't have to care about anything else
and no need to re-emerge anything).

(BTW, the usage of this flag in net-proxy/squid really is special, don't quite
understand why not just use the rotate functionality squid itself has.)

So, please nuke the use flag and install the stuff unconditionally.

see #198901 and gentoo-dev for more info.