Read both {energy,charge}_now and {energy,charge}_full to determine battery status

[jens-na]

lifebar uses the following files to determine the battery status:

• /sys/class/power_supply/BAT0/energy_full
• /sys/class/power_supply/BAT0/energy_new

According to this thread on the Linux ACPI Development Discussion List there are probably other files available under certain circumstances:

• /sys/class/power_supply/BAT0/charge_full
• /sys/class/power_supply/BAT0/charge_new

This pull request now covers both energy_* and charge_* files. What do you think?

[lynks--]

Looks great, thanks :) I'll merge this a little later on.

[jens-na]

Great, thanks. :sparkles: