Patch for https://bugs.php.net/bug.php?id=44522 to allow uploading files
above 2G.

This is essentially the same as the patch
"uploads_larger_than_2g_HEAD_v2 (last revision 2012-03-26 03:59 UTC) by
jason at infininull dot com)" but using off_t instead of signed long
(originally: uint)

I tested this on 64bit linux and succeeded uploading a file of 4.8 G.
The File did not get corrupted or truncated in any way.

I did not yet test this under windows or 32 bit linux

Note that there are still limitations:

* Did not test for files > 8 G
* php does not yet reject absurdly high values
* Still limited by underlying file system specific limits and free space
* in upload
* tmp dir and destination dir
ws
Use int64_t and atoll() after discussion with johannes
make this work in vc11 too
more precise condition
add NEWS entry; add simple test