Potential fix for problem encoding with x264

[mean]

If you have problem encoding with x264, where the 2nd pass fails with "bitrate too low" error, please try the following :
http://avidemux.org/nightly/win_installer/avidemux_2.6.5_r8932_win32.exe
(32 bits only)

It might (or not) help the maxxed out bitrate problem also

Short explanation:
* Avidemux internally works in UTF8, windows work in utf16
* There are some function to convert to/from utf8<->utf16 on windows
* x264 only works with ascii
* Previously avidemux converted utf8 to ascii for x264 but it does not work well enough

Now
* x264 has been patched to work with utf8
* There are in fact 2 patches :
       - one that works with opening files (old one)
       - one that works when renaming file (brand new). Without the 2nd one,  first pass was ok but failed with some .temp files left in the folder

Feedback welcome

[mean]

win64 version
http://avidemux.org/nightly/win_installer/avidemux_2.6.5_r8932_win64.exe