float window notepad adversion

Invalid date

v16
Changed icon
window will become half transparent after inactivated
Support background change.
Move the path to /mnt/sdcard/settings/WNP/
put any image file in this path and rename it to mynote.png to change the background img
put font file in this path and rename it to mynote.ttf to change the note font
The text color will be decided as the inverse color of the average color of the background.