ffmpeg: update 3.3.2

- ffmpeg 3.3 -> 3.3.2
- added VERSIONINFO

3rdparty/ffmpeg/ffmpeg.cmake

-# Binary branch name: ffmpeg/master_20170418
-# Binaries were created for OpenCV: b993b9b7c7f6f5f37d10acacb2962812228410ba
-set(FFMPEG_BINARIES_COMMIT "86c4a841055f2612774e85b4292bb20e5fe8a783")
-set(FFMPEG_FILE_HASH_BIN32 "3dea5f7f009b44601fe95728328e0f9e")
-set(FFMPEG_FILE_HASH_BIN64 "9debe701975ef074bd6661981f3f0716")
-set(FFMPEG_FILE_HASH_CMAKE "208c00f03d2f6f39fa6262649e0bfc8d")
+# Binary branch name: ffmpeg/master_20170704
+# Binaries were created for OpenCV: f670a9927026629a4083e05a1612f0adcad7727e
+set(FFMPEG_BINARIES_COMMIT "a86e53eb35737a50e5100e26af3aa1d29e810890")
+set(FFMPEG_FILE_HASH_BIN32 "79c35cc654778e66237444bc562afbca")
+set(FFMPEG_FILE_HASH_BIN64 "0dc72775ec3c14d1e049f51dc1280dbb")
+set(FFMPEG_FILE_HASH_CMAKE "ec59008da403fb18ab3c1ed66aed583b")
 
 function(download_win_ffmpeg script_var)
   set(${script_var} "" PARENT_SCOPE)

3rdparty/ffmpeg/readme.txt

@@ -16,19 +16,18 @@
   The binaries are opencv_ffmpeg.dll (version for 32-bit Windows) and
   opencv_ffmpeg_64.dll (version for 64-bit Windows).
 
-  See build_win32.txt for the build instructions, if you want to rebuild opencv_ffmpeg*.dll from scratch.
-
   The pre-built opencv_ffmpeg*.dll is:
   * LGPL library, not BSD libraries.
   * Loaded at runtime by opencv_videoio module.
     If it succeeds, ffmpeg can be used to decode/encode videos;
     otherwise, other API is used.
 
-  FFMPEG build contains H264 encoder based on the OpenH264 library, that should be installed separatelly.
+  FFMPEG build includes support for H264 encoder based on the OpenH264 library.
   OpenH264 Video Codec provided by Cisco Systems, Inc.
   See https://github.com/cisco/openh264/releases for details and OpenH264 license.
-  Downloaded binary file can be placed into global system path (System32 or SysWOW64) or near application binaries.
-  You can also specify location of binary file via OPENH264_LIBRARY_PATH environment variable.
+  OpenH264 library should be installed separatelly. Downloaded binary file can be placed into global system path
+  (System32 or SysWOW64) or near application binaries (check documentation of "LoadLibrary" Win32 function from MSDN).
+  Or you can specify location of binary file via OPENH264_LIBRARY environment variable.
 
   If LGPL/GPL software can not be supplied with your OpenCV-based product, simply exclude
   opencv_ffmpeg*.dll from your distribution; OpenCV will stay fully functional except for the ability to