[PATCH v2 0/3] Allow building Git with Asciidoctor

This series is designed to implement the changes necessary to build Git using Asciidoctor instead of AsciiDoc.

The first two patches are bug fixes, and are unchanged from v1. Asciidoctor is stricter about some aspects of formatting, and these patches are required to make the documentation build correctly.

The third patch moves several pieces of the documentation makefile into variables. Some of these changes were suggested by Junio, and some of them were required to simply build correctly.

In this patch, I have maintained the ASCIIDOC_HTML and ASCIIDOC_DOCBOOK variables, because otherwise there is no way to override the backends easily, which is required to build. For Asciidoctor, there is no xhtml11 backend and the docbook backend produces DocBook 5, which xmlto doesn't like.

The fourth patch in the previous series has been dropped, as Dan Allen of the Asciidoctor project has pointed me to a backend-agnostic implementation of the linkgit macro which is included in the Asciidoctor project. The litdd attribute, the only other missing piece, can be moved to the command line, so the patch became unnecessary.

I've successfully built the documentation with Asciidoctor using the following command line:

  make doc ASCIIDOC=asciidoctor ASCIIDOC_HTML=html5 \
  ASCIIDOC_DOCBOOK=docbook45 ASCIIDOC_EXTRA="'-alitdd=--'" \
  ASCIIDOC_CONF=

This resulted in a total build time (documentation only) of 3:17 versus 5:43 for AsciiDoc (a 42% improvement).

brian m. carlson (3):
  Documentation: adjust document title underlining
  Documentation: fix mismatched delimiters in git-imap-send
  Documentation: move some AsciiDoc parameters into variables

 Documentation/Makefile             | 26 +++++++++++++++-----------
 Documentation/git-imap-send.txt    |  4 ++--
 Documentation/git-prune-packed.txt |  2 +-
 Documentation/git-quiltimport.txt  |  2 +-
 Documentation/git-stage.txt        |  2 +-
 5 files changed, 20 insertions(+), 16 deletions(-)