Proper support of completing an edit in the middel of an expression.
Also support 'noProperty' mode in the completer, where no completion is
offered for property names. This will be used by tree view object
search.
* Display property from linked object, colored green,
* Change DlgPropertyLink to support external linking and sub-object
selection
* Improve large selection performance by using a timer
* Improve TAB key behavior in property editor
* Add context menu to show hidden properties, change property status,
set expression on any and property, and add/remove dynamic properties
* Optimize expression completer model construction, as the original
implementation gets prohibitively slow for moderate number of objects.
QString::fromAscii() is obsolete in Qt5. Replace it with fromLatin1().
QString::toAscii() is obsolete in Qt5. Replace it with toLatin1().
QChar::fromAscii() is obsolete in Qt5. Replace it with fromLatin1().
This change is Qt4/Qt5 neutral.