added simple logger instead of using cerr for messages

Ignore-this: 6acf3c5819f9f297e8f0a14aa735cd12

For now just creates a log file under the log folder in the firestr home directory.
No rolling log yet.

darcs-hash:20130325185353-c21fe-e3dfd34aef225fc852b0c3361868511216adb66a