SAMZA-46
Improve the state management documentation.
Misc. tweaks to the state management docs at Tejas' suggestion.
Misc. improvements to the state management docs.
fix simpe->simple typo on index page.
SAMZA-51; Fix simple typo on web index
SAMZA-25; adding metrics to everything.
SAMZA-2; adding pluggable message chooser.
SAMZA-52; cleaning up build.gradle to allow for custom overrides. also fixing jacoco and idea plugin issues.
SAMZA-28; fixing bug in blocking envelope map metrics.
SAMZA-53: Extraneous import breaks compilation.
SAMZA-54; fix sporadically failing test in blocking envelope map.
SAMZA-55; make string serde handle null objects.
SAMZA-56; add an integer serde.
BUG FIX; minor issue with SAMZA-56 commit with Scala 2.8.1.
SAMZA-57; fix npe in serialized key value store.
SAMZA-9; upgrading samza to yarn 2.2.0.
updating rules docs
SAMZA-62; retry on offset request failures in kafka checkpoint manager.
updating readme as part of SAMZA-9 YARN 2.2 upgrade.