Set  parameter's (basic) properties for a report

It should be possible to define the properties of each parameter of a report.

The properties that should be set are te following
- visible (true/false) - PromptUser
- default-value - DefaultValue

Expect syntax:

``` xml
<report ...>
   <parameter name="Alpha" visible="false" default-value="1"/>
   <parameter name="Beta" visible="true" default-value="BEL"/>
</report>
```
