Serde fix and Scalding source for HCatalog

There are essentially two changes here: 1) I removed the dependency on Hive's lookupDeserializer() method, and 2) I added a Scalding source that uses the HCatalog tab and scheme, instead of directly accessing the ORCFile or RCFile.

In the process, I reformatted the pom.xml file a bit, and removed the inclusion of Hive classes into the built jar. I also bumped the dependencies to bring Cascading and Scalding up to the current released version. However, I changed the Hadoop dependency to the latest in the 2.4.x series, since we are still on Hadoop 2.4. I didn't try testing it with the Hadoop 2.5 dependency.

The reason I embarked on this mission was to resolve the persistent classpath issues I was having using this extension out of the box. I could not get it to work using the hadoop command with -libjars, nor with the hive wrapper script, because of either missing classes in the former, or the duplicate SerDeUtils class in the latter. So I decided to remove the SerDeUtils class from this code, and run my jobs using the Hive wrapper script, which properly sets up the Hadoop classpath with all of Hive and HCatalog's jars.