Adding exclusions has legitimate uses but can also cause problems. But here exclusions are being removed -- which conversely could also cause problems. 

The motivation was to avoid warnings since "*" syntax generates a warning in Maven, even though it should be OK. But, I looked into it and had reason to believe the exclusions were actually unnecessary, or even not quite right:

- "sisu" exclusion is a no-op since I can't find it anywhere in the dependency tree
- "xerial.snappy" exclusion excludes the same version of the artifact the project uses, so also has no practical effect
- "jackson" exclusion seemed to be in the wrong place to achieve what I think is its goal of excluding version 1.8.8. So it was moved and "unrolled" to avoid * syntax

This is indeed the only bit of this change that I think could cause a problem, so would like @rxin 's eyes on it too. But, the logic seemed OK per above.