#14 pyml 0.7.8 fixes for gcc 4.6.1

[Thomas Dziedzic]

# fix PyML/classifiers/ext/libsvm_wrap.cpp:2856:13: error: ‘ptrdiff_t’ does not name a type
sed \ -e '14i#include <cstddef>' \ -i PyML/classifiers/ext/libsvm_wrap.cpp

# fix PyML/utils/ext/arrayWrap_wrap.cpp:2641:13: error: ‘ptrdiff_t’ does not name a type
sed \ -e '13i#include <cstddef>' \ -i PyML/utils/ext/arrayWrap_wrap.cpp

[abh]

Thanks for proposing a fix!