Merge branch 'sk/wincred'

* sk/wincred:
  wincred: avoid overwriting configured variables
  wincred: add install target

contrib/credential/wincred/Makefile

@@ -1,14 +1,22 @@
 all: git-credential-wincred.exe
 
-CC = gcc
-RM = rm -f
-CFLAGS = -O2 -Wall
-
 -include ../../../config.mak.autogen
 -include ../../../config.mak
 
+CC ?= gcc
+RM ?= rm -f
+CFLAGS ?= -O2 -Wall
+
+prefix ?= /usr/local
+libexecdir ?= $(prefix)/libexec/git-core
+
+INSTALL ?= install
+
 git-credential-wincred.exe : git-credential-wincred.c
 	$(LINK.c) $^ $(LOADLIBES) $(LDLIBS) -o $@
 
+install: git-credential-wincred.exe
+	$(INSTALL) -m 755 $^ $(libexecdir)
+
 clean:
 	$(RM) git-credential-wincred.exe