tests: use $TEST_DIRECTORY to refer to the t/ directory

Many test scripts assumed that they will start in a 'trash' subdirectory
that is a single level down from the t/ directory, and referred to their
test vector files by asking for files like "../t9999/expect".  This will
break if we move the 'trash' subdirectory elsewhere.

To solve this, we earlier introduced "$TEST_DIRECTORY" so that they can
refer to t/ directory reliably.  This finally makes all the tests use
it to refer to the outside environment.

With this patch, and a one-liner not included here (because it would
contradict with what Dscho really wants to do):

| diff --git a/t/test-lib.sh b/t/test-lib.sh
| index 70ea7e0..60e69e4 100644
| --- a/t/test-lib.sh
| +++ b/t/test-lib.sh
| @@ -485,7 +485,7 @@ fi
|  . ../GIT-BUILD-OPTIONS
|
|  # Test repository
| -test="trash directory"
| +test="trash directory/another level/yet another"
|  rm -fr "$test" || {
|         trap - exit
|         echo >&5 "FATAL: Cannot prepare test area"

all the tests still pass, but we would want extra sets of eyeballs on this
type of change to really make sure.

[jc: with help from Stephan Beyer on http-push tests I do not run myself;
 credits for locating silly quoting errors go to Olivier Marin.]

Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9111-git-svn-use-svnsync-props.sh

@@ -8,7 +8,7 @@ test_description='git-svn useSvnsyncProps test'
 . ./lib-git-svn.sh
 
 test_expect_success 'load svnsync repo' '
-	svnadmin load -q "$rawsvnrepo" < ../t9111/svnsync.dump &&
+	svnadmin load -q "$rawsvnrepo" < "$TEST_DIRECTORY"/t9111/svnsync.dump &&
 	git-svn init --minimize-url -R arr -i bar "$svnrepo"/bar &&
 	git-svn init --minimize-url -R argh -i dir "$svnrepo"/dir &&
 	git-svn init --minimize-url -R argh -i e "$svnrepo"/dir/a/b/c/d/e &&