* Involves rearranging some header includes to break cyclic include dependencies,
* Adding a new, simple base class CEmpty,
* Removing any remaining polymorphic uses of CValueObject with templates,
* Adding a new trait for use with enable_if to restrict templates to work only with value objects,
* Replacing the polymorphic/runtime multimethod-based compare functions with static/compile-time compare functions.
Also refs #351
* messages can be formatted with style sheet
* fixed: removed command from message
* added originator to command line
* msg parsing now in core
* using ITimestampBased for text messages and status messages
* allow to resize rows to content (view base)
* model / views for text messages
* removed old qt stylesheets
* support of property index
* used support classes BlackMisc::ITimestampBased, ITimestampObjectList and ICallsignObjectList
* fixed some issues in related aircraft situation class in same step
* consolidated ICoordinateGeodetic (e.g. fixed nested properties)
* shifted common functionality for objects/containers with callsign into interface
* shifted common functionality for objects/containers with geo position into interface
* shifted common functionality for objects/containers with timestamp into interface
* updated corresponding value objects / specialized lists
* adjusted all places where renamed functions are used
* Start index 10 instead 0 for CValueObject (easier to detect bugs)
* Fixed wrong indexes
* Asserts in CPropertyIndex
* Used Icon instead of QPixpmap with indexes, icons are sortable and have a tooltip
* Removed redundant toQVariant methods
* renamed fromQVariant to convertFromQVariant, the "from" methods imply the object is changed (fromJson, fromString ..)
* implemented fromQVariant - changing the object by QVariant
* moved toQVariant into PQ template
* free function setFromQVariant
