File++

- ozCore
  * File
    + data is mutable, (un)map() is const
    + inputStream() implicitly maps file to memory
    + cp()
- client
  * Shape::tag() fixed
Text textures rendered without 1-frame lag

- ui
  * Text textures are generated and rendered without 1-frame lag
  * Label::setXXX() functions simplified, clear() added
  * CreditsMenu scrolling fixed