This is an major version release that contains all the bug fixes and improvement
in 0.5.4 and 0.6.1. 0.7.0 also make lots of performance and scalability enhancement like
1) Reduce AM mem usage caused by storing TezEvents
2) Stabilize and improve the Pipeline shuffle,  make PipelienedSorter as the default sorter,
3) Remove 2 GB memlimit restriction in MergeManager
4) Enable local fetch optimization by default
Please see CHANGES.txt for more details.