[OE-core] opencv 2.4 build failure

[Bruce, Henry]

Thanks to Alexander Kanavin's patch I can now start an opencv build on
master without the x11 distro feature. However the build fails in the
python module as NPY_SIZEOF_OFF_T is not defined. 

[ 89%] Building CXX object
modules/python/CMakeFiles/opencv_python.dir/src2/cv2.cpp.o
...
In file included from build/tmp/sysroots/intel-corei7
-64/usr/lib/python2.7/site
-packages/numpy/core/include/numpy/ndarraytypes.h:4:0,
                 from build/tmp/sysroots/intel-corei7
-64/usr/lib/python2.7/site
-packages/numpy/core/include/numpy/ndarrayobject.h:18,
                 from build/tmp/work/corei7-64-poky
-linux/opencv/2.4.11+gitAUTOINC+2c9547e314
-r0/git/modules/python/src2/cv2.cpp:15:
build/tmp/sysroots/intel-corei7-64/usr/lib/python2.7/site
-packages/numpy/core/include/numpy/npy_common.h:149:10: error: #error
Unsupported size for type off_t
         #error Unsupported size for type off_t
          ^

I'm not enough of python guy to fix this myself. Where should I start
looking? 

Thanks,

Henry Bruce