add sample script samples/basic/memcpy_memset.kp

This script is for histgram memcpy/memset size output,
to get know which size is operated most frequently.

Signed-off-by: Jovi Zhangwei <jovi.zhangwei@gmail.com>
pass event filter correctly

Pass the event filter string "filter", not "/filter/"

Signed-off-by: Jovi Zhangwei <jovi.zhangwei@gmail.com>
add test for event filter parse

Signed-off-by: Jovi Zhangwei <jovi.zhangwei@gmail.com>