- Don't enforce sequentiality constraint on SEND_RESCHED samples.
- Refuse samples with negative time deltas (possible due to clock skew).

Timestamps and sequence numbers should be monotonic with regard to a
single CPU and/or or task. Non-compliant samples were disturbed and
should be rejected.

The -s flag prevents ftsort from writing back results to disk.  The -v
(verbose) flag enables more detailed output.  These flags are useful
when debugging traces and filtering.

Interrupts can cause massive outliers. Instead of trying to filter
them afterwards, let's not even include such samples in the first
place.

...to mirror those used in the kernel.