Fixed boundary check in file/slice
Updated file/stat to use the internal fd
Fumbled around with tests, they need major rewrite

Seriously, they were utterly fucked since the very beginning.
Defragment, compartmentalize, group and order.
Added 'flags' param to writeStream, prevents trunc

Node defaults to 'w' on writeStreams, which effectively
truncates your file whenever you do a streamed write.
This fixes it. Now defaults to 'r+'.
Added bound checks for file/slice in streams
0.6.0