v1.2.0 - `include` overhaul + slow script detection

Changelog

See wiki for the detailed description of API changes.

Added

• Improved include method:
  • Added support for relative paths.
  • Added script caching - script file will be read only once from filesystem (even if it is included from different panels).
    Improves panel initialization speed when re-using same script files.
  • Added include guard - script won't be evaluated a second time if it was evaluated before in the same panel (handled by new options.always_evaluate argument).
• Added slow script handling: script can be aborted now if it's unresponsive for some time.

Changed

• Improved performance of utils.FileTest(path, 's').

Fixed

• Fixed crashes in Thumbs and Album Art complete samples (by @marc2k3).
• Fixed GdiBitmap.GetColourScheme not limiting the number of output colours.
• Fixed potential memory leaks when using window.NotifyOthers.
• Fixed fb2k freeze on exit.
• Fixed invalid colour calculation in GdiBitmap.GetColourSchemeJSON.
• Fixed colour rounding errors in GdiBitmap.GetColourScheme and GdiBitmap.GetColourSchemeJSON (kudos to @kbuffington).