remote-testgit: move it into the support directory for t5801

The `git-remote-testgit` script is really only used in
`t5801-remote-helpers.sh`. It does not even contain any `@@<MAGIC>@@`
placeholders that would need to be interpolated via `make
git-remote-testgit`.

Let's just move it to a new home, decluttering the top-level directory
and clarifying that this is just a test helper, not an official Git
command that we would want to ever support.

Suggested by Ævar Arnfjörð Bjarmason.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

.gitignore

@@ -135,7 +135,6 @@
 /git-remote-ftps
 /git-remote-fd
 /git-remote-ext
-/git-remote-testgit
 /git-remote-testpy
 /git-remote-testsvn
 /git-repack

Makefile

@@ -633,7 +633,6 @@ SCRIPT_SH += git-merge-resolve.sh
 SCRIPT_SH += git-mergetool.sh
 SCRIPT_SH += git-quiltimport.sh
 SCRIPT_SH += git-legacy-rebase.sh
-SCRIPT_SH += git-remote-testgit.sh
 SCRIPT_SH += git-request-pull.sh
 SCRIPT_SH += git-stash.sh
 SCRIPT_SH += git-submodule.sh
@@ -657,8 +656,6 @@ SCRIPT_PERL += git-svn.perl
 
 SCRIPT_PYTHON += git-p4.py
 
-NO_INSTALL += git-remote-testgit
-
 # Generated files for scripts
 SCRIPT_SH_GEN = $(patsubst %.sh,%,$(SCRIPT_SH))
 SCRIPT_PERL_GEN = $(patsubst %.perl,%,$(SCRIPT_PERL))

t/t5801-remote-helpers.sh

@@ -8,6 +8,8 @@ test_description='Test remote-helper import and export commands'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-gpg.sh
 
+PATH="$TEST_DIRECTORY/t5801:$PATH"
+
 compare_refs() {
 	git --git-dir="$1/.git" rev-parse --verify $2 >expect &&
 	git --git-dir="$3/.git" rev-parse --verify $4 >actual &&