Average data usage widget

Invalid date

---Note: if the widget stops responding, just restart the device or delete and then add the widget again.----

V 2.0
- History activity: you can view the usage on each day of the period. Button from the main widget opens this.
- Accumulate option. Enable this if your provider saves the unused data for the next period.
- New main screen, separated options to secondary one.
- Small tweaks for the size and view of the widgets.