Spark bundles various third-party sources. Some of these require additional attribution besides the inclusion of the copyright statements that are already in the source files. Therefore, a top-level NOTICE file should be added. This will also help consumers of Spark know which attributions they should give for the new transitive dependencies they are taking.
Fixed #233, Add top-level NOTICE file:
- Renamed LICENSE to NOTICE
- Added Apache 2 license as LICENSE
- Added notices from all bundled software