Please describe the problem:
The applications uses a high CPU load when searching for empty lines with PERL regexp syntax.

Steps to reproduce:
1. Open a document with at least one empty line
2. Open the Replace dialog and search for ^$ (empty line)
3. Select the PERL regexp syntax
4. Submit


Actual results:
- Application uses high CPU load
- Application does actually not replace the empty line

Expected results:
Replace the empty line by the wanted string

Does this happen every time?
yes

Other information:
Bluefish is really great and this is my first bug report !