Also removed some unnecessary comments

Closes #480

This removes the need for the private Couchbase repository since the
1.4.10 criver is available in Maven Central.

Adapted from #172

- define checkstyle configs in as few places as possible
- use checkstyle:check since it has defaults that match what we want (fail after logging to console)
- modules that have current failures set property checkstyle.failOnViolation to false.

[core accumulo couchbase memcached] Fixing squid:S1155 - Collection.isEmpty() should be used to test for emptiness

Replaces numeric status codes with a canonical set of Status objects,
each with a short name and description.
Bindings with more specific errors (e.g., timeouts) return additional
statuses.

This changes the default output from messages like:

   [UPDATE], Return=0, 511

To:

   [UPDATE], Return=OK, 511

As a part of branching to stage 0.2.0 release in #266, set version
for continued development on master branch.

* remove unused declared deps in a few places
* lex sort modules in top level pom
* update maven plugin versions.
* no more jar-with-dependencies
* set ycsb-core to provided in bindings
* introduce a bindings-parent pom that sets
** stage dependency copy on building binding
** iff binding has a README.md, build a binding-specific dist artifact
* update distribution assembly to
** properly build after modules
** use per-binding sets of dependencies

closes #250

closes #136

Signed-off-by: Sean Busbey <sean.busbey@gmail.com>