Optimizations + Upgrade to Hadoop 2.2.0, add custom InputFormat and OutputFormat - V2

This PR mainly makes the following changes:

1. Set Hadoop version to 2.2.0 and make certain changes to prevent compile errors and move from deprecated API to newer API.
2. Some changes like **Use broadcast for Language object; wrap mapper using SparkUtils.kryoWrapFunction** and **Move ontology, disambiguation, commonsSource vals to createExtraction...** were made to solve serialization issues.
3. Various small changes like making writing of intermediate `RDD[WikiPage]` to cache optional/configurable, registering all the classes that Kryo needs to serialize to improve performance and reduce serialization footprint etc. were made.
4. Replace `XmlInputFormat` with a custom InputFormat called `DBpediaWikiPageInputFormat` (which uses two classes, `SeekableInputStream` and `ByteMatcher`) that supports compressed input. It also supports **splittable** compression methods like bz2 which is a huge benefit for us. Here's how: say we have this input file, *enwiki-latest-pages-articles-multistream.xml.bz2*. It's > 10GB. It's compressed such that Hadoop's splittable input stream implementations can break it into chunks and decompress them on the fly *parallely*. Parallel decompression and subsequently parallel operations on the data. Refer to discussion on https://github.com/dbpedia/distributed-extraction-framework/pull/27 for details. This is not anything fancy, but something that most InputFormats have to do. Hadoop's own built-in InputFormat implementations do stuff like this too.
5. A custom OutputFormat called `DBpediaCompositeOutputFormat`) is used to write outputs in parallel instead of streaming it over the master iteratively and writing to Hadoop FileSystem - this obviously eliminates a big performance bottleneck. `WikiPageWritable` is a Hadoop `Writable` implementation that wraps a `WikiPage` and handles its serialization/deserialization. Similarly, `QuadSeqWritable` wraps a `Seq[Quad]` - this one is used for writing outputs.

I think we're ready for reviewing and merging to master, and then asking the community to test this out.
Check if serializing the existing Config object and sending it to the Distributed Cache is better than sending the config file and creating all the formatters again. Benchmark the overhead.