Ticket #47387 - improve logconv.pl performance with large access logs

https://fedorahosted.org/389/ticket/47387
Reviewed by: mreynolds (Thanks!)
Branch: master
Fix Description: The primary fix is to use tied hashes and arrays backed by
DB_File database files.  Hashes use DB_HASH and arrays use DB_RECNO.  These
fixes cut down the time by a factor of 10 or more, and considerably reduce
the size of the disk files.  There is still room for optimization as given
by the Devel::NYTProf package, but this should at least give us acceptable
performance.
I also did some perl "linting" - running with use warnings and use strict -
which revealed a lot of code which was cleaned up.
Platforms tested: RHEL6 x86_64
Flag Day: no
Doc impact: no