Forms: Policy for implementing default widget set

• All common widgets are included

• When new widget is to be included, and it's dependent on too new KDE version (or Qt version) - the widget needs to be backported with all it's user-visible properties and features. Otherwise Kexi projects will not be portable enough.

Example of such backporting is now with KDateWidget, etc. (KDE 3.2.x) that for KDE 3.1 are substituted by QDateEdit, etc (thanks to source-compatibility between those). Other widgets that may not be avalilable in Qt -then the only way to fix this is to grab the widget's sources from KDE project and backport, including into Kexi source.