Merge branch 'sg/fix-versioncmp-with-common-suffix'

The prereleaseSuffix feature of version comparison that is used in
"git tag -l" did not correctly when two or more prereleases for the
same release were present (e.g. when 2.0, 2.0-beta1, and 2.0-beta2
are there and the code needs to compare 2.0-beta1 and 2.0-beta2).

* sg/fix-versioncmp-with-common-suffix:
  versioncmp: generalize version sort suffix reordering
  versioncmp: factor out helper for suffix matching
  versioncmp: use earliest-longest contained suffix to determine sorting order
  versioncmp: cope with common part overlapping with prerelease suffix
  versioncmp: pass full tagnames to swap_prereleases()
  t7004-tag: add version sort tests to show prerelease reordering issues
  t7004-tag: use test_config helper
  t7004-tag: delete unnecessary tags with test_when_finished

diff --cc Documentation/config.txt
Simple merge

diff --cc Documentation/git-tag.txt
Simple merge

diff --cc t/t7004-tag.sh
Simple merge