Hello Dia developers,

I've attached a patch (created against the current svn version) which
adds a new sheet called 'Database' with some new objects/shapes to Dia.
It is ment for drawing database table relation diagrams. Here's a short
description of the new objects/shapes:

- Table:
A table is very similar to an UML class. Indeed I used the code of the
UML class implementation to create the table object. In addition to some
properties like line-color, line-width etc. the table object has a
variable length list of attributes.

- Reference:
Is a simple orthogonal connection with an description at the beginning
and end point. Only the end point can have an arrow drawn. Of course, it
is ment to display a foreign key reference.

- Compound:

To be able to create foreign key reference which are composed of
multiple table attributes I created the compound object. The component
is quite general and can be used for other purposes, too. It is like a
spider. There is one connection point and many arms starting at the
connection point. Currently, there is a very simple algorithm to place
the initial position of the arms.