Fixed path.clear() (for real, this time)
Fix an instance where GetLastError was not called in Process module.
Remove return from windows thread stub as it was used incorrectly and does not work on 64 bit, the return value from the thread run is saved in the object anyway.
Make cmake only add -march=i486 for 32 bit mingw as it breaks mingw64 builds and is unneeded with 64 bit anyway.
Adapt use of EAGAIN and EINPROGRESS to work cross platform between windows and posix.