Incorporate upstream bugfixes.
lirc.spec: %sysconfdir -> /etc, localstatedir->/var

New packaging guidelines allowes this much cleaner approach.
lirc.spec: Remove redundant Requires(post, postun).
lirc.spec: Remove caraca TODO (upstream is dead).
lirc.spec: Remove config files TODO. They are fine as-is.
lirc.spec: Reorganize %install.
lirce.spec: Kill rpmlint warning macro in comment.
lirc.spec: Remove very old update fixes.
lirc.spec: Add comments on rpmlint warnings.
lirc.spec: rm -rf $RPM_BUILD_ROOT is not required.
lirc.service -> lircd.service: Renamed main service.

To be consistent with docs, configuration files, sockets etc.
Adding systemd socket activation support

After systemd entering the scene many clients have problems
with trying to attach to the lircd socket before it's
created. The correct solution is socket activation in which
the sockets are created by systemd before any client has a chance
to access it.
lirc.spec: Don't claim temporary files in /run/lirc.