ktrace issues

[justincormack]

ktrace works as proof of concept but has a lot of issues

1. add rest of trace types
2. add rest of syscall numbers
3. need to be able to introspect argument and return value types so can work out which are eg ints not long
4. special case handling for multiple return values
5. friendlier output (see ioctl rough example)

[justincormack]

Also some issue with ktr_header.pid on 32 bit - fixed, version issue but see #117

[justincormack]

Fix tests to test stuff not print it out.

[justincormack]

make util.kdump take an fd or filename and allocate buffer itself.

[justincormack]

__tostring method on ktr_header