[HttpFoundation] Fixed byte ranges in the BinaryFileResponse.

According to rfc2616 (http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35.1)
byte positions are inclusive:

The first-byte-pos value in a byte-range-spec gives the byte-offset of
the first byte in a range. The last-byte-pos value gives the byte-offset
of the last byte in the range; that is, the byte positions specified are
inclusive. Byte offsets start at zero.

src/Symfony/Component/HttpFoundation/BinaryFileResponse.php

@@ -199,7 +199,7 @@ public function prepare(Request $request)
                 list($start, $end) = array_map('intval', explode('-', substr($range, 6), 2)) + array(0);
 
                 if ('' !== $end) {
-                    $this->maxlen = $end - $start;
+                    $this->maxlen = $end - $start + 1;
                 } else {
                     $end = $this->file->getSize() - 1;
                 }

src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php

@@ -61,7 +61,7 @@ public function testRequests()
         $request->headers->set('If-Range', $etag);
         $request->headers->set('Range', 'bytes=1-4');
 
-        $this->expectOutputString('IF8');
+        $this->expectOutputString('IF87');
         $response = clone $response;
         $response->prepare($request);
         $response->sendContent();