ChangeLog: added include/exclude support to filter uninteresting files

This change allows to explicitly include/exclude files from the change sets.
If the filter removes all files from a given change set, the whole change set is omitted. 
This is useful to ignore commits on resources that are not interesting for the report. Can be configured like this:

    <includes>
        <include>src/main/java/*.java</include>
    </includes>
    <excludes>
        <exclude>src/test/**</exclude>
    </excludes>