[Logging] filters are ignored if you set them after setting level

Steps to reproduce:
1. Create a TraceTarget instance
2. set level property
3. set filters property

Please see a detailed description at: http://blog.adamcreeger.com/2008/08/logging-in-flexair-two-strange-things.html

Actual Results:
The filters are being ignored.

Expected Results:
Filters not being ignored.

Workaround (if any):
You have to set your filters before you set your level.