dynamic fsync: favor true case since most will be using this feature

Signed-off-by: Paul Reioux <reioux@gmail.com>
overall_stats: add overall stats for all available cores

this is much more accurate stats tracking than just displaying core 0's
stats from most other kernels

Signed-off-by: faux123 <reioux@gmail.com>
overall_stats: make dual/quad core stats configurable via meunconfig

Signed-off-by: faux123 <reioux@gmail.com>