[PATCH V2 0/5] Add PCRE support to git-grep

This patch series attempts to add PCRE support to git-grep.

Changes from previous version:

* Now this series start from two patches which add the --line-number
  option to SYNOPSIS and bash completion; they can be treated
  separatedly from this series

* All patches have improved descriptions

* All patches have Signed-off-by

* libpcre specific code has been moved to a separate subsection to
  reduce number of #ifdefs; this addresses comments from Junio

* I noticed that even though I call pcre_study(), I didn't use its
  result in pcre_exec(); now this is fixed; this should improve
  git-grep --perl-regexp performance

* --perl-regexp has been added to bash-completion

* Added last patch which adds checks for libpcre to configure

* I repeated `make test` with and without pcre few more times and I
  cannot reproduce results from previous runs; possibly they were
  altered by current system load or cold cache. Now the difference
  is just few seconds. However, I'm still not convinced to link
  libgit.a with libpcre.

Michał Kiedrowicz (5):
  Documentation: Add --line-number to git-grep synopsis
  contrib/completion: --line-number to git grep
  grep: Put calls to fixmatch() and regmatch() into patmatch()
  git-grep: Learn PCRE
  configure: Check for libpcre

 Documentation/git-grep.txt             |    8 ++-
 Makefile                               |   16 +++++
 builtin/grep.c                         |    2 +
 config.mak.in                          |    1 +
 configure.ac                           |   26 ++++++++
 contrib/completion/git-completion.bash |    3 +-
 grep.c                                 |  100 +++++++++++++++++++++++++++++---
 grep.h                                 |    9 +++
 8 files changed, 154 insertions(+), 11 deletions(-)