fix rpm spec file

* eliminate rpmlint warnings

* comply with fedora packaging guidelines
  http://fedoraproject.org/wiki/Packaging:SourceURL#Github

* remove refs to patches that are not in the upstream repo
  - logrotate source is not in repo
  - patches are not in repo
  - cron is not in repo

* use root/rancid instead of rancid/rancid for file ownership,
  addressing annoyance after fresh install:

    [root@j01 ~]$ rpm --verify rancid-git
    .....U...    /etc/rancid
    .....U...  c /etc/rancid/lg.conf
    .....U...  c /etc/rancid/rancid.conf
    .....U...    /var/log/rancid
    .....U...    /var/log/rancid/old
    .....U...    /var/rancid

* convert configure.in to configure for rpmbuild

  upstream spec file does not build as-is.
  we need to use autoconf and friends to create the `configure` script

* comment-out AM_C_PROTOTYPES

  avoid de-ansification, similar to:
  http://git.yoctoproject.org/cgit.cgi/poky/plain/meta/recipes-support/gmp/gmp-4.2.1/gmp_fix_for_automake-1.12.patch
use tito to build rpm

https://github.com/dgoodwin/tito is a tool for managing RPM based
projects using git for their source code repository.
Automatic commit of package [rancid-git] release [2.3.8-0].