[PATCH 0/10] color and pager improvements

[Jeff King <peff@peff.net>]

While looking at the pager and color code today, I decided to tackle two
long-standing bugs, which entailed a lot of refactoring of the color
code. The result fixes some minor bugs, and is a little nicer for
calling code to use.

  [01/10]: t7006: modernize calls to unset
  [02/10]: test-lib: add helper functions for config
  [03/10]: t7006: use test_config helpers

These three are just cleanup I noticed before adding new tests to t7006;
I hope that the helpers in 02/10 will be useful in a lot of other
places, though.

  [04/10]: setup_pager: set GIT_PAGER_IN_USE

This fixes Ingo's problem from:

  http://article.gmane.org/gmane.comp.version-control.git/179430

Namely that:

  git -p stash show

fails to use colors properly.

  [05/10]: diff: refactor COLOR_DIFF from a flag into an int
  [06/10]: git_config_colorbool: refactor stdout_is_tty handling
  [07/10]: color: delay auto-color decision until point of use

These three fix the problem Steffen mentioned here:

  http://article.gmane.org/gmane.comp.version-control.git/177792

Namely that pager.color doesn't work in many cases. This has been a
problem for years, but spread due to some pager-ordering changes late
last year (see the comments in 07/10). I actually wonder if anyone is
really using pager.color, as we haven't seen many complaints about it.

  [08/10]: config: refactor get_colorbool function
  [09/10]: diff: don't load color config in plumbing
  [10/10]: want_color: automatically fallback to color.ui

These three are refactoring that is made possible by 07/10. I think they
make the code cleaner, and hopefully the diffstat of 10/10 speaks for
itself.

-Peff