D-5

v-2.5a
---
1. show position list in videos#view

	==> done
D-5

v-2.5b
---
1. sort position list

	==> done
D-5

v-2.5c
---
1. new PHP func => conv_SecToTimeLabel()

	==> done
D-5

v-2.5c(re)
---
1. new PHP func => conv_SecToTimeLabel()

	==> done
D-5

v-2.4c(re)
---
1. Video#add => add field: "Genre"

	==> done
Merge branch 'D-5_save/retrieve_currentTime'