Adds Caching paper on 2Q algorithm

The algorithm was referenced in an article about
improving buffer cache replacement in OpenBSD.

http://www.tedunangst.com/flak/post/2Q-buffer-cache-algorithm

The article was found on the vldb.org website via a google
search.

http://www.vldb.org/conf/1994/P439.PDF
Add a link to https://lobste.rs/t/pdf
updates reference to paper
Merge pull request #170 from csaunders/master

Adds Caching paper on 2Q algorithm
Merge pull request #172 from 3rdman/master

Add a link to https://lobste.rs/t/pdf
add papers from peter burka, including the one he'll present in nyc, *crossing-the-gap*
Merge pull request #174 from papers-we-love/@pburka-papers

add papers from peter burka, including the one he'll present in nyc, *cr...