ansicolors: expose disable() function
Reporters: add -R plain:no-color option (#318)
reporters/plain: code readability improved
Reporters: add -R tap:no-skip option (#318)
Reporters: add -R statsd:<host>:<port>:<prefix> options (#318)
README: update -R statsd example
Reporters: add -R elasticsearch:<host>:<port>:<index>:<type> options (#318)
README.md: s/ElasticSearch/Elasticsearch/g
Reporter: do not add numeric values as keys
Merge pull request #337 from macbre/reporter-options-round-2

 Implement next set of reporter options