output issue urls when they are mentioned in chat

[benwtr]

totally untested, just wrote this here, probably won't work on the first try:

robot.hear /(?:gh|github) issue #(\d+)(?: in ([\w\d-_]+)(?:\/([\w\d-_]+))?)?/i, id:'gh-issues.mention', (msg) ->
  id = msg.match[1]
    repo = if msg.match[2]? and msg.match[3]?
    "#{msg.match[2]}/#{msg.match[3]}"
  else if msg.match[2]?
    "#{DEFAULT_OWNER}/#{msg.match[2]}"
  else
    "#{DEFAULT_OWNER}/#{DEFAULT_REPO}"
  robot.ghissues.showIssue msg, id, repo

So you should then be able to mention issues in a chat:

User> So I says to Mabel, I says check out gh issue #4832742 in hubot-scripts/hubot-gh-issues
Hubot> Issue #4832742 in hubot-scripts/hubot-gh-issues - foo - https://github.com/hubot-scripts/hubot-gh-issues/issue/4832742

[benwtr]

One problem here is users that aren't authenticated. There could be a default "bot" credential for this, or it could only work for authenticated users. I think option 2 is better.