Install contrib/diff-highlight (#1550251)

The script is installed at /usr/share/git-core/contrib/diff-highlight.
Documentation is in /usr/share/doc/git/contrib/diff-highlight/README.

(cherry picked from commit 440594446e)

git.spec

@@ -45,7 +45,7 @@
 
 Name:           git
 Version:        2.14.3
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        Fast Version Control System
 License:        GPLv2
 Group:          Development/Tools
@@ -417,6 +417,8 @@ make -C contrib/credential/libsecret/
 %endif
 make -C contrib/credential/netrc/
 
+make -C contrib/diff-highlight/
+
 make -C contrib/subtree/
 
 # Remove shebang from bash-completion script
@@ -474,6 +476,11 @@ find %{buildroot} -type f -name perllocal.pod -exec rm -f {} ';'
 # Clean up contrib/credential to avoid cruft in the git-core-doc docdir
 rm -rf contrib/credential
 
+# install contrib/diff-highlight and clean up to avoid cruft in git-core-doc
+install -Dpm 0755 contrib/diff-highlight/diff-highlight \
+    %{buildroot}%{_datadir}/git-core/contrib/diff-highlight
+rm -rf contrib/diff-highlight/{Makefile,diff-highlight,*.perl,t}
+
 # Clean up contrib/subtree to avoid cruft in the git-core-doc docdir
 rm -rf contrib/subtree/{INSTALL,Makefile,git-subtree{,.{1,html,sh,txt,xml}},t}
 
@@ -609,6 +616,7 @@ rm -rf %{buildroot}
 %{elispdir}
 %{_emacs_sitestartdir}/git-init.el
 %endif
+%{_datadir}/git-core/contrib/diff-highlight
 %{_datadir}/git-core/contrib/hooks/update-paranoid
 %{_datadir}/git-core/contrib/hooks/setgitperms.perl
 
@@ -618,7 +626,8 @@ rm -rf %{buildroot}
 #      be used elsewhere
 %{!?_licensedir:%global license %doc}
 %license COPYING
-# exlude is best way here because of troubels with symlinks inside git-core/
+# exclude is best way here because of troubles with symlinks inside git-core/
+%exclude %{_datadir}/git-core/contrib/diff-highlight
 %exclude %{_datadir}/git-core/contrib/hooks/update-paranoid
 %exclude %{_datadir}/git-core/contrib/hooks/setgitperms.perl
 %{bashcomproot}
@@ -739,6 +748,9 @@ rm -rf %{buildroot}
 # No files for you!
 
 %changelog
+* Thu May 24 2018 Todd Zullinger <tmz@pobox.com> - 2.14.3-4
+- Install contrib/diff-highlight (#1550251)
+
 * Fri Feb 16 2018 Todd Zullinger <tmz@pobox.com> - 2.14.3-3
 - git-svn: avoid segfaults in 'git svn branch'