Prints an alert message on center of your screen when buffed/debuffed by specified buff.

The command it supports are:
/rba addb effect_id message
    set an alert message when you're buffed(I call it Begin-alerting).
/rba adde effect_id message
    set an alert message when specified buff disappear(I call it End-alerting).
/rba list
    list alert messages.
/rba delb effect_id
    clear specified Begin-alerting message.
/rba dele effect_id
    clear specified End-alerting message.
/rba off
    temporary disable buff alerting
/rba on
    enable buff alerting
/rba debug
    toggle debug mode (for finding effect_id)

Currently it's still a dumb addon, you have to find out the buff's effect_id in following steps:
1. use "/rba debug" to toggle debug mode of this addon, ensure you're in debug mode.
2. in debug mode, each time you're buffed, it'll print an short message like this: "[BuffAlert] THE_NAME_OF_THIS_BUFF (numeric_effect_id)"
3. remember th effect_id you want.
4. use commands above to setup(or clear) alert messages.

As in latest alpha(also means buggy for me lol) release, a new command "/rba show" is added. This command prints a list in chat window, which contains currently enabled buff with their effect_id. The original idea is from Kolakhan (see comments below).

Thanks to AceFramework! It's so easy to add l10n support with AceLocale!