Adds support for utf paths on Windows.

Not all file formats/calls are supported yet. It will be expended.

Please from now on use BLI_fopen, BLI_* for file manipulations.
For non-windows systems BLI_fopen just calls fopen.
For Windows, the utf-8 string is translated to utf-16 string in order to call UTF version of the function.

intern/utfconv/SConscript

@@ -0,0 +1,12 @@
+#!/usr/bin/python
+Import ('env')
+
+sources = env.Glob('*.c')
+
+incs = '.'
+defs = ''
+
+
+
+if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'linuxcross', 'win64-vc'):
+    env.BlenderLib ('bf_utfconv', sources, Split(incs), Split(defs), libtype=['intern','player'], priority=[0,0] )