Test clean-up.

* sb/cd-then-git-can-be-written-as-git-c:
  lib-submodule-update.sh: reduce use of subshell by using "git -C"

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

"git diff" learned diff.interHunkContext configuration variable
that gives the default value for its --inter-hunk-context option.

* vn/diff-ihc-config:
  diff: add interhunk context config option

Error message fix.

* sb/submodule-init:
  submodule update --init: display correct path from submodule

Test updates.

* sb/submodule-config-tests:
  t7411: test lookup of uninitialized submodules
  t7411: quote URLs

Tighten a test to avoid mistaking an extended ERE regexp engine as
a PRE regexp engine.

* jk/grep-e-could-be-extended-beyond-posix:
  t7810: avoid assumption about invalid regex syntax

"git mergetool" without any pathspec on the command line that is
run from a subdirectory became no-op in Git v2.11 by mistake, which
has been fixed.

* rh/mergetool-regression-fix:
  mergetool: fix running in subdir when rerere enabled
  mergetool: take the "-O" out of $orderfile
  t7610: add test case for rerere+mergetool+subdir bug
  t7610: spell 'git reset --hard' consistently
  t7610: don't assume the checked-out commit
  t7610: always work on a test-specific branch
  t7610: delete some now-unnecessary 'git reset --hard' lines
  t7610: run 'git reset --hard' after each test to clean up
  t7610: don't rely on state from previous test
  t7610: use test_when_finished for cleanup tasks
  t7610: move setup code to the 'setup' test case
  t7610: update branch names to match test number
  rev-parse doc: pass "--" to rev-parse in the --prefix example
  .mailmap: record canonical email for Richard Hansen

Running "git add a/b" when "a" is a submodule correctly errored
out, but without a meaningful error message.

* sb/pathspec-errors:
  pathspec: give better message for submodule related pathspec error

Test cleanup.

* pb/test-must-fail-is-for-git:
  t9813: avoid using pipes
  don't use test_must_fail with grep

"git push \\server\share\dir" has recently regressed and then
fixed.  A test has retroactively been added for this breakage.

* js/mingw-test-push-unc-path:
  mingw: add a regression test for pushing to UNC paths