SCORE-181. Determine how we can encode the per-request parameters in the model_container

issue: https://jira.kiji.org/browse/SCORE-181
review: https://review.kiji.org/r/1883
Update versions for release
[maven-release-plugin] prepare release kiji-scoring-0.16.0
[maven-release-plugin] prepare for next development iteration
SCORE-183. Add command line for how to set the base_url_key

issue: https://jira.kiji.org/browse/SCORE-183
review: https://review.kiji.org/r/1985
POM-40. Require JDK 7 to compile Kiji projects

issue: https://jira.kiji.org/browse/POM-40
review: https://review.kiji.org/r/2027
Add pluggable counters