GEOMESA-62 Adding ability to modify and remove features from the AccumuloFeatureStore

Added the ability to modify and remove features in Accumulo.
GEOMESA-74 Change Geoserver Plugin to hide password

PR # - Base_Branch:master
GEOMESA-75 Change Geoserver Plugin to allow blank Auths param
Merge branch 'master' into geomesa-73-wip