Added new configuration option to colorize sent messages depending on the current and previous states of job.

[syl20bnr]

Checking this box allows the bot to send colorized messages depending on the
current and previous states of a job.

The bot tries to send green messages for successful jobs
and red messages for failures but this may not be right
if your IRC client has defined a custom theme of colors.

Here are the rules for coloring messages:

    Starting previously successful job: green
    Starting previously fixed job: olive
    Starting previously failed job: red
    First successful build (fixed job): green background
    First failure: red background
    Still successful job: bold green
    Still failing job: bold red
    Default message: bold gray

There is no support for colorblind theme for now.

[buildhive]

Jenkins » ircbot-plugin #9 SUCCESS
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