testsuite: use binary output mode for custom curl test tools

Do not try to convert line-endings to CRLF on Windows by setting stdout
to binary mode, just like the curl tool does if --ascii is not specified.

This should prevent corrupted stdout line-ending output like CRCRLF.

In order to make the previously naive text-aware tests work with
binary mode on Windows, text-mode is disabled for them if it is not
actually part of the test case and line-endings are corrected.

tests/data/test578

@@ -8,18 +8,18 @@ HTTP POST
 #
 # Server-side
 <reply name="1">
-<data mode="text">
-HTTP/1.1 200 OK
-Date: Thu, 09 Nov 2010 14:49:00 GMT
-Server: test-server/fake
-Last-Modified: Tue, 13 Jun 2000 12:10:00 GMT
-ETag: "21025-dc7-39462498"
-Accept-Ranges: bytes
-Content-Length: 6
-Connection: close
-Content-Type: text/html
-Funny-head: yesyes
-
+<data>
+HTTP/1.1 200 OK
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake
+Last-Modified: Tue, 13 Jun 2000 12:10:00 GMT
+ETag: "21025-dc7-39462498"
+Accept-Ranges: bytes
+Content-Length: 6
+Connection: close
+Content-Type: text/html
+Funny-head: yesyes
+
 -foo-
 </data>
 </reply>
@@ -45,7 +45,7 @@ http://%HOSTIP:%HTTPPORT/500 log/ip578
 #
 # Verify data after the test has been "shot"
 <verify>
-<file name="log/ip578" mode="text">
+<file name="log/ip578">
 PASSED, UL data matched data size
 </file>
 </verify>