D-17

v-3.3.4
---
1. seekbar
2. pref => current position
    ==> pref reset when the actv stopped

    ==> done
D-17

v-3.3.5
---
1. play file => start from the pref position

    ==> done
D-17

v-3.3.6a
---
1. SB

    ==> going
D-17

v-3.3.6b
---
1. TRY: instantiate in play_File

    ==> done