Added profile "code-coverage" to run cobertura-maven-plugin

It could be useful to check code coverage and cobertura-maven-plugin will do it.

I've added new profile "code-coverage". You need to activate it and run "mvn clean package" to build report about code coverage. Report about code coverage is available in "target/site/cobertura".

![image](https://f.cloud.github.com/assets/578021/2237965/3c093b62-9bd3-11e3-9917-f796a8eced26.png)