Update to work with Clojure 1.3 & other fixes

[alexott]

These changes includes:

• get rid of not necessary clojure-contrib dependency
• use of clj-serializer 0.1.3 that was fixed to work with clojure 1.3.0
• fix exception when as-table was used with instance of HTablePool$PooledHTable

[chawco]

I have another pull req that builds on this, adds support for check-and-put and some initial support for versions. Is there anyone maintaining this upstream? I'm a little hesitant to put together the pull req unless someone is able to approve a merge.

[eslick]

I am no longer working with HBase regularly so not actively maintaining it. I'd be OK accepting patches, but would prefer if someone else who is actively using the library took it over.