systemdzbus 0.1.4

Interact with systemd through DBus with a convenient rust interface. All of the initial types were automatically generated by the CLI tool 'zbus-xmlgen'. From here I just copied the documentation from the systemd man page to get good descriptions for each function.
Documentation
# Systemdzbus

Interact with systemd through DBus with a convenient rust interface.
The manager proxy types were generated by 'zbus-xmlgen'.
From here I just copied the documentation from the systemd man page to
get good descriptions for each function.

The plan is to wrap all useful functionality in nice to use types.

## Usage

```rust
    use std::error::Error;
    use systemdzbus::{SystemCtl, ConnectionLevel};

    async fn example_get_units() -> Result<(), Box::<dyn Error>> {
        let mut systemctl = SystemCtl::new(ConnectionLevel::UserLevel);
        systemctl.init().await?;

        let units = systemctl.list_units().await?;

        assert!(!units.is_empty());
        Ok(())
    }
```

## Purpose

The entire use of this project was for me to get better documentation for the automatic
types generated by 'zbus-xmlgen' and to have a nice interface on top of the raw manager proxy.