ftp tests: provide LIST responses in the test file itself

Previously LIST always returned a fixed hardcoded list that the ftp
server code knew about, mostly since the server didn't get any test case
number in the LIST scenario. Starting now, doing a CWD to a directory
named test-[number] will make the test server remember that number and
consider it a test case so that a subsequent LIST command will send the
<data> section of that test case back.

It allows LIST tests to be made more similar to how all other tests
work.

Test 100 was updated to provide its own directory listing.

tests/data/test100

@@ -11,11 +11,11 @@ LIST
 <reply>
 # When doing LIST, we get the default list output hard-coded in the test
 # FTP server
-<datacheck>
+<data>
 total 20
 drwxr-xr-x   8 98       98           512 Oct 22 13:06 .
 drwxr-xr-x   8 98       98           512 Oct 22 13:06 ..
-drwxr-xr-x   2 98       98           512 May  2  1996 .NeXT
+drwxr-xr-x   2 98       98           512 May  2  1996 curl-releases
 -r--r--r--   1 0        1             35 Jul 16  1996 README
 lrwxrwxrwx   1 0        1              7 Dec  9  1999 bin -> usr/bin
 dr-xr-xr-x   2 0        1            512 Oct  1  1997 dev
@@ -23,7 +23,7 @@ drwxrwxrwx   2 98       98           512 May 29 16:04 download.html
 dr-xr-xr-x   2 0        1            512 Nov 30  1995 etc
 drwxrwxrwx   2 98       1            512 Oct 30 14:33 pub
 dr-xr-xr-x   5 0        1            512 Oct  1  1997 usr
-</datacheck>
+</data>
 </reply>
 
 #
@@ -36,7 +36,7 @@ ftp
 FTP dir list PASV
  </name>
  <command>
-ftp://%HOSTIP:%FTPPORT/
+ftp://%HOSTIP:%FTPPORT/test-100/
 </command>
 </client>
 
@@ -47,6 +47,7 @@ ftp://%HOSTIP:%FTPPORT/
 USER anonymous
 PASS ftp@example.com
 PWD
+CWD test-100
 EPSV
 TYPE A
 LIST