#1 Implicit class replacement

[William R]

By using the "class" attribute, the class used for a component can be changed (if this component accepts all the methods of the original one). Some companies have developped their own swing components bqsed on the original ones. The XML should add a <classes> tag where the original classes can be replaced by the new ones not on a specific basis but for all the tags.
Note: this can be done at the configuration level but the usage of ENTITIES can avoid a declaration to be done on all the XML description file.

[William R]

Validated and will be added. Nevertheless changes are quite huge.