contrib/linux-wheel-centos5-blacklist

templatekw: introduce obsfate keyword

Introduce an obsfate printer that uses all helpers functions defined in
obsutil to get all the obsfate-related data and format a string according to
the current format in test-obsmarker-template.t.

Then, introduce an obsfate templatekw that uses the obsfateprinter to return a
list of strings.

The goal is not to replace existing obsfate template functions but to propose
a default, good-enough and easily usable obsfate definition for end-users that
don't want to customize it. Such output would ultimately get included in the
default log output.

Here are some output examples for a commit amended:

rewritten using amend as 5:a9b1f8652753 by test (at 1970-01-01 00:00 +0000)

Next patches will make the output dependent on the verbosity.

Exemple of use-cases:

For having the obsfate on a single-line between brackets:

  {if(obsfate, " [{join(obsfate, "; ")}]")}

For having the obsfate in several lines:

  {if(obsfate, "{obsfate % "  Obsfate: {fate}\n"}")}

test-convert-git.t
test-subrepo-git.t
test-patchbomb-tls.t