Description of problem:
When you comment some code in dslr file, the expander still tries to expand it.

Version-Release number of selected component (if applicable):
BRMS-5.2.0.CR1

How reproducible:
Every time

Steps to Reproduce:
1. create rule that has expansion problems
2. comment it in /* */ block
3. try to add incriminated files (DSL + DSLR) to knowledge builder
  
Actual results:
Exception during building (Unable to expand...)

Expected results:
Commented rules are skipped and package parsed as ussual

Additional info:
use example from Bug 742893