Allow escape codes for color formatting messages

[kallisti5]

You can't directly put escape codes into the pipeline yaml, (you get "error: yaml: control characters are not allowed")

but irc-notification-resource could translate escaped colors for you using a common method.
https://github.com/myano/jenni/wiki/IRC-String-Formatting

Example:

# Jobs
jobs:
  - name: haiku-((branch))-((arch))
    public: true
    on_success:
      put: irc
      params:
        message: \x0303((branch)) build of ((arch)) was successful!\x0F ${BUILD_URL}
    on_failure:
      put: irc
      params:
        message: \x0304((branch)) build of ((arch)) failed!\x0F ${BUILD_URL}
    plan:

It looks like it wouldn't be super hard to "search for \xYY in a message and change it to 0xYY in the string.

[kallisti5]