This patches some issues with the capture engine:
1. Check is the engine is open in ctrace commands.
2. Check all record open and appends for overflow.
3. Fix the record open to take the size of user data and
not the record header.
4. Use packed structs for data being written to the per
cpu buffers.
5. Remove direct struct access to the capture buffers to
avoid misaligned accesses.
6. Add support to extract records, no struct access to the
capture buffers.
7. Update ctrace to extract records from the capture buffers.
8. Add support to ctrace to always print the task name if it
has one.
9. Add support to manage names or the lack of a name.
10. Range of minor fixes.
11. Fix a long standing bug in ctset's handling of args.
Closes#2780.
