Merge branch 'jc/color' into next

* jc/color:
Add colordiff for git to contrib/colordiff.
Makefile: dependency for builtin-help.o

diff --combined Makefile
index ab021eddbd3f3f827fe373806a9001e07130a9c9,d9a3a82fe2afa2bb477d65f082b6348ed678e955..25b99e62d1c891fe9d1185eb3cc7648fe811835a
--- 1/Makefile
--- 2/Makefile
+++ b/Makefile
@@@ -470,6 -470,8 +470,8 @@@ git$X: git.c common-cmds.h $(BUILTIN_OB
                $(ALL_CFLAGS) -o $@ $(filter %.c,$^) \
                $(BUILTIN_OBJS) $(ALL_LDFLAGS) $(LIBS)
  
+ builtin-help.o: common-cmds.h
+ 
  $(BUILT_INS): git$X
        rm -f $@ && ln git$X $@
  
@@@ -609,9 -611,6 +611,9 @@@ test-date$X: test-date.c date.o ctype.
  test-delta$X: test-delta.c diff-delta.o patch-delta.o
        $(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $^ -lz
  
 +test-gsimm$X: test-gsimm.c gsimm.o rabinpoly.o
 +      $(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $^
 +
  check:
        for i in *.c; do sparse $(ALL_CFLAGS) $(SPARSE_FLAGS) $$i || exit; done
  
@@@ -660,7 -659,6 +662,7 @@@ clean
        rm -f *.o mozilla-sha1/*.o arm/*.o ppc/*.o compat/*.o xdiff/*.o \
                $(LIB_FILE) $(XDIFF_LIB)
        rm -f $(ALL_PROGRAMS) $(BUILT_INS) git$X
 +      rm -f test-date$X test-delta$X test-gsimm$X
        rm -f *.spec *.pyc *.pyo */*.pyc */*.pyo common-cmds.h TAGS tags
        rm -rf $(GIT_TARNAME)
        rm -f $(GIT_TARNAME).tar.gz git-core_$(GIT_VERSION)-*.tar.gz