Support for system wide icons

[JoeStanziano]

This plugin is currently not following Apple's Alternate App Icon guidelines.

Add support for changing the app icon system wide.

4.6 Alternate App Icons Apps may display customized icons, for example, to reflect a sports team preference, provided that each change is initiated by the user and the app includes settings to revert to the original icon. All icon variants must relate to the content of the app and changes should be consistent across all system assets, so that the icons displayed in Settings, Notifications, etc. match the new springboard icon. This feature may not be used for dynamic, automatic, or serial changes, such as to reflect up-to-date weather information, calendar notifications, etc.

[johnborges]

@JoeStanziano I'll fix the readme instructions since it isn't very clear on this topic.

The plugin will change the icons in those other areas you mentioned (settings, notifications, spotlight), as long as you provide the appropriate resolutions for those additional icons.

Something to try as an example:

1. Create a couple icons: icon, icon@2x, icon@3x.
2. Only specify one icon reference in Info.plist for all resolutions

<key>CFBundleIcons</key>
<dict>
    <key>CFBundleAlternateIcons</key>
    <dict>
        <!-- The name you use in code -->
        <key>my-app-icon</key>
        <dict>
            <key>UIPrerenderedIcon</key>
            <true/>
            <key>CFBundleIconFiles</key>
            <array>
                <!-- the actual filename -->
                <string>icon</string>
            </array>
        </dict>
    </dict>
</dict>