wincred: add install target

Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Acked-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/credential/wincred/Makefile

@@ -7,8 +7,16 @@ CFLAGS = -O2 -Wall
 -include ../../../config.mak.autogen
 -include ../../../config.mak
 
+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