This completely reworks the sysinfo module to add support for aggregate functions, better support for working with individual devices, the ability to specify units, and some string formatting support.
Several new tokens have also been added, and performance should be marginally improved.
BREAKING CHANGE: Use of the `sys_info` module in your config will need to be updated to use the new token format. See the wiki page for more info.
BREAKING CHANGE: To allow for the `name` property, any widgets that were previously targeted by name should be targeted by class instead. This affects **all modules and all popups**, as well as several widgets inside modules. **This will break a lot of rules in your stylesheet**. To attempt to mitigate the damage, a migration script can be found [here](https://raw.githubusercontent.com/JakeStanger/ironbar/master/scripts/migrate-styles.sh) that should get you most of the way.
Resolves#75.
BREAKING CHANGE: This renames the module from `sys-info` to `sys_info`, and almost every formatting token from `kebab-case` to `snake_case`. Any use of this module will need to be updated.
