Hadoop 2.0 compatibility, hive 0.10

 - Using ContextUtils to be able to launch with hadoop 2.0
 - Working with hive 0.10
 - Fix some issues with ArrayWritable to be able to reach any columns
with objectInspector
Add metadata in ReadContext instead of Split

- Fix TaskAttemptContext in the deprecated output format
- Clean up a bit how we get the split in the deprecated input format
Clean up ReadSupport init
Manage count 0
Update with advices from Julien
Improve speed for queries like count(0), in which we only need the number of lines
Try to fix travis build
Minor changes

 - Documentation
 - Change the name of a method
Update getSplits in DeprecatedParquetInputFormat

- In the case of a FileSplit, do not get the blocks, and instead
compute directly from the split offset/length
- Add javadoc
Code review

 - Add todo
 - Add javadoc
 - Rename class
 - Rename method
 - Improve tests