[PATCH v2 0/7] more ANSI attributes

Here's a re-roll of my earlier patches to add "italic" support.

It fixes the documentation problem Junio mentioned (along with some other issues there). It also cleans up parse_attr() to make it a bit easier to read and maintain, and adds a few more features.

  [1/7]: color: fix max-size comment
  [2/7]: doc: refactor description of color format
  [3/7]: add skip_prefix_mem helper
  [4/7]: color: refactor parse_attr
  [5/7]: color: allow "no-" for negating attributes
  [6/7]: color: support "italic" attribute
  [7/7]: color: support strike-through attribute

-Peff