@tarkah im pretty happy with the outcome of this PR. Please let me know what you think.

@casperstorm looks good. I've added some comments but it's small stuff. I need to do some testing still. Awesome job!

How and where should we check for newly added paths? One way is to do the following:

    // Check if any new flavor has been added since last time.
    // Get missing flavors.
    let mut missing_flavors: Vec<&Flavor> = vec![];
    for flavor in Flavor::ALL.iter() {
        if let None = ajour.config.wow.directories.get(flavor) {
            missing_flavors.push(flavor);
        }
    }

    let flavors = &ajour.config.wow.directories.keys().collect::<Vec<_>>();
    for flavor in flavors {
        // Find root dir of the flavor and check if any of the missing_flavor's is there.
        // If it is, we added it to the directories.
        if let Some(root_dir) = ajour.config.get_root_directory_for_flavor(flavor) {
            for missing_flavor in &missing_flavors {
                let flavor_dir = ajour
                    .config
                    .get_flavor_directory_for_flavor(missing_flavor, &root_dir);
                if flavor_dir.exists() {
                    ajour
                         .config
                         .wow
                         .directories
                         .insert(**missing_flavor, flavor_dir);
                }
            }
        }
    }

How and where should we check for newly added paths? One way is to do the following:

    // Check if any new flavor has been added since last time.
    // Get missing flavors.
    let mut missing_flavors: Vec<&Flavor> = vec![];
    for flavor in Flavor::ALL.iter() {
        if let None = ajour.config.wow.directories.get(flavor) {
            missing_flavors.push(flavor);
        }
    }

    let flavors = &ajour.config.wow.directories.keys().collect::<Vec<_>>();
    for flavor in flavors {
        // Find root dir of the flavor and check if any of the missing_flavor's is there.
        // If it is, we added it to the directories.
        if let Some(root_dir) = ajour.config.get_root_directory_for_flavor(flavor) {
            for missing_flavor in &missing_flavors {
                let flavor_dir = ajour
                    .config
                    .get_flavor_directory_for_flavor(missing_flavor, &root_dir);
                if flavor_dir.exists() {
                    ajour
                         .config
                         .wow
                         .directories
                         .insert(**missing_flavor, flavor_dir);
                }
            }
        }
    }

Agreed, lets put this under the Parse message so it checks everytime the user launches or refreshes

@tarkah i've added the logic we discussed now. I found another case I solved as well. As i see it this is the QA:

• You should not see a "Welcome to Ajour" when coming from a previous version. Check settings to see if mapping was successful.
• Adding a new path to a flavor you don't have works.
• You can see addons in the new path.
• Adding a new path, to an already existing flavor should overwrite it.
• You can see addons in the new (overwritten) path.
• Removing a known flavor path should remove it during refresh.
• Adding a new flavor to a known path should add it automatically.