From: Dmitriy Morozov <dmitriy@mrzv.org>
Date: Mon, 18 Apr 2011 15:41:53 -0700
State: new
Subject: Configurable format
Message-Id: <af5b63a7d86cf9e3-0-artemis@vine>

The user should be able to define the format for the issue summary line (in
ilist) in the config file. So, for instance, one could specify:

  [artemis]
  format = %(id)s (%(len)3d) [%(state)s]: %(Subject)s

to have the default (current) format. One should also be able to specify
additional conditions with the flags in the name of the option. For example:

  format:state=in-progress    = %(id)s (%(len)3d) [%(state)s; priority=%(priority)s]: %(Subject)s
  format:state=resolved       = %(id)s (%(len)3d) [%(state)s=%(resolution)s]: %(Subject)s
  format:state=resolved&resolution=fixed  = %(id)s (%(len)3d) [fixed]: %(Subject)s    # also change color
  format:state=fixed          = ...  # change color

The format string would be passed the headers from the root message, so that
the user could use whatever properties she wanted.

This approach would also replace the current way we define colors.