* TextBox now supports selecting.
    * Click and drag
    * Shift + arrow keys
    * Shift + home
    * Shift + end
* Nothing can be done with selected text currently.
* Added uiimplementers.  These will be an approximation of the bridge design pattern.  Each UIImplementer will contain functionality
    which can be used by a UIComponent through composition. This will allow for desired functionality to be added to components
    quickly and easily.
* Currently ui.textbox.TextBox has a ui.uiimplementers.TextSelecter
* There are plans to move caret functionality into an implementer as well
* Added ui.text.SelectableText which extends ui.text.Text