build: generate and clean test scripts

Commit 416fda69 (build: do not install git-remote-testpy) made it so
git-remote-testpy is not only not installed, but also not generated
by default.  From a fresh checkout, "make --test=5800 test" would
have failed.

This was not found primarily because "make clean" failed to remove
git-remote-testpy, which is another bug in the same commit.

Fix the former by having 'all' target depend on $(NO_INSTALL) and
the latter by removing $(NO_INSTALL) in the 'clean' target.
Signed-off-by: NFelipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Makefile

@@ -2205,6 +2205,7 @@ endif
 test_bindir_programs := $(patsubst %,bin-wrappers/%,$(BINDIR_PROGRAMS_NEED_X) $(BINDIR_PROGRAMS_NO_X) $(TEST_PROGRAMS_NEED_X))
 
 all:: $(TEST_PROGRAMS) $(test_bindir_programs)
+all:: $(NO_INSTALL)
 
 bin-wrappers/%: wrap-for-bin.sh
 	@mkdir -p bin-wrappers
@@ -2454,7 +2455,7 @@ clean: profile-clean
 	$(RM) *.o block-sha1/*.o ppc/*.o compat/*.o compat/*/*.o xdiff/*.o vcs-svn/*.o \
 		builtin/*.o $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB)
 	$(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) git$X
-	$(RM) $(TEST_PROGRAMS)
+	$(RM) $(TEST_PROGRAMS) $(NO_INSTALL)
 	$(RM) -r bin-wrappers $(dep_dirs)
 	$(RM) -r po/build/
 	$(RM) *.spec *.pyc *.pyo */*.pyc */*.pyo common-cmds.h $(ETAGS_TARGET) tags cscope*