algorithm: refine insert sort

Signed-off-by: Yibo Cai <cyb70289@gmail.com>
Makefile: echo -e

Signed-off-by: Yibo Cai <cyb70289@gmail.com>
include: fix tt_min & tt_max

Signed-off-by: Yibo Cai <cyb70289@gmail.com>
algorithm: add merge sort

Signed-off-by: Yibo Cai <cyb70289@gmail.com>
tests: refine sort testing

Generate random array and test sorting algorithms automatically with
run time comparison.

Signed-off-by: Yibo Cai <cyb70289@gmail.com>