Better nsq configuration

* Refactored configuration validation
* Added tests for new configuration validation
* Added support for other nsq ```IDENTIFY``` options
* Updated documentation
* Bumped version
Document breaking change
Use `@constructor` instead of `this.constructor`
Fix typo
Remove unused conditions call
Bump npm version
Simple number check for `isNumber`
Fix README typo. Add msg_timeout support in README
Merge master
Merge pull request #33 from dudleycarr/refactor-config

Better configuration validation and support