TODO

* QDaqDataBuffer
  * Not implemented: A QDaqDataBuffer with QDaqChannels correctly write to & read from h5 file

* script extensions
    * core makes a lib with no widgets - only ref to widgets
    * QDaqSession does not have widget-related functions
    * all widgets got into "gui" module libQDaqGui.so
    * there is a qdaq_gui plugin that defines the qscript interface and can be imported to a session
    * this goes to qt5/plugins/script/libQDaq_script_gui.so with keys: ["qdaq", "qdaq_qui"] that depends on libQDaqGui.so
    * availableExtensions("qdaq") would list all extensions
    * similar for "interfaces", "filters", ...

* load/save properties and file version, e.g. QDaqDataBuffer prop "type" changed. how to load from old file??
  * type marshalling in setQDaqProperty - handle special cases like ByteArray, Vector, etc...
  * History file to start with a .
  * Syntax checking in scripts and report to user
  * Implement editing of QDaq Types in property browser. Need to subclass QtVariantEditorFactory.
    Current solution: properties are displayed read-only as a text string
  * Session error log output should go also to stderr
  * qdaq errors should also go to stderr
  * when IDE is closed and opened after error, the error is not displayed
  * error queue object has to be updated
  * Syntax highlighting in console widgets
  * Ui window browser similar to QDaq object browser