Some Int-based tests, and fixes to work with 0.9.0-SNAPSHOT

- Updated key-value tests to also allow aggregate and sort on ints
- Updated SBT assembly to work properly with 0.8/0.9's assembly (the previous one crashed due to an issue with META-INF/LICENSE)
- When linking with Spark, don't package *all* the JARs in the Spark directory; just take its assembly JAR
- Updated paths to target directories