[PATCH take 3 0/4] color-words improvements

This series is getting bigger and bigger, unfortunately, just what I tried to avoid.

But at least I am pretty comfortable with the readability of the result, and it adds tests -- finally.

Changes relative to the last round: color_fwrite_lines() had problems with empty lines, and find_word_boundary() was replaced by find_word_boundaries(), which finds not only the end of the next word, but the start, too.

The only "funny" thing I realized is that the lines which are output by emit_line() add a RESET at the end of the line, and I do not do that in color_fwrite_lines().

Can anybody think of undesired behavior as a consequence?

Johannes Schindelin (4):
  Add color_fwrite_lines(), a function coloring each line individually
  color-words: refactor word splitting and use ALLOC_GROW()
  color-words: change algorithm to allow for 0-character word
    boundaries
  color-words: take an optional regular expression describing words

 Documentation/diff-options.txt |    6 +-
 color.c                        |   28 ++++++
 color.h                        |    1 +
 diff.c                         |  203 ++++++++++++++++++++++++++--------------
 diff.h                         |    1 +
 t/t4034-diff-words.sh          |   86 +++++++++++++++++
 6 files changed, 253 insertions(+), 72 deletions(-)
 create mode 100755 t/t4034-diff-words.sh