Updated documentation.

Documented `--web-host` in the output of `--help` command.

Reshuffled sections in `readme.md`, updated dependencies, expanded list
of features and known issues.

Fixes strongloop/node-inspector#19.
Added AUTHORS

List of authors as reported by
  `git log --pretty=format:"%an <%ae>" | sort -u > AUTHORS`
(Plus moved Danny Coates to the first line.)
Added MAINTAINERS.md file

Described steps for releasing a new version of node-inspector.