[Radiance-general] file locking on windows

[Ignacio Munárriz]

hi all, a week ago, i tried to use rpiece on windows and i got the "no NFS
lock manager" message, so i`ve implemented file locking on windows with the:
UnlockFile(HANDLE,DWORD,DWORD,DWORD,DWORD)  and
LockFile(HANDLE,DWORD,DWORD,DWORD,DWORD)  functions.

Now i've a rpice.exe running on windows, maybe it could be useful for rpict
ambient file locking, but i havent gave a look on it yet, if anybody is
interested on the code i'll clean and upload it