Colour-formatted messages with leading digits aren't always rendered as expected

#### Steps to Reproduce
###### Input
    #httyd.14-12-10.log:341:01:58 < puxlit> toothless! learn test -> 123
    #httyd.14-12-10.log-342-01:58  * Toothless has been trained by puxlit!
    #httyd.14-12-10.log-343-01:58 < puxlit> test

###### Expected Output
    #httyd.14-12-10.log-344-01:58  * Toothless 123

* "123" should be green.

###### Actual Output
    #httyd.14-12-10.log-344-01:58  * Toothless 23

* "23" is not "123".
* "23" is not green.

#### Details
With [ircutils 0.1.4](https://pypi.python.org/pypi/ircutils/0.1.4), colour-formatting text comprises prepending messages with the relevant escape character and colour index. Since two-digit colour indices exist, IRC clients may misinterpret a single-digit colour index concatenated with a message comprising leading digits, unless the single-digit colour index is zero-padded to two digits.

Since [ircutils](https://pypi.python.org/pypi/ircutils) appears to be no longer maintained, we may have to fix this internally.