Modified the common starting paragraph of all tutorials to make more sense.
Added new tutorial 09 - Poll Result Analysis - Write and Run Your own YARN Job
Changed YARN to MapReduce since the example is a custom MapReduce application.
Fixed a typo
Changed Application Code to use ToolRunner
Renamed file
Merge pull request #21 from vivganes/tutorial-branch

Added new tutorial : Code your own MapReduce Job using Java