Improvements

[GreatTA1998]

    <li>Support arbitrary pen colors for blackboard</li>
    <li>Fix scrolling on blackboard not always working</li>
    <li>Ultra-large blackboard</li>
    <li>Pinned blackboard toolbar</li>
    <li>Cache blackboards you already opened to not have to wait for it to load</li>
    <li>Don't display initials/middle names as last names</li>
    <li>Merge multiple devices from same users into one user</li>