Several API addings
Added process.cpp, process.h and utilsunx.cpp in wxMMedia directory
They should be moved to src/unix, src/common and include/wx to use them
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@6280 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775