Allow the setting of a specific build failure threshold by package.

Let's say my application is layered in 3 layers, Model, Views, Controllers and that my package names are like com.company.Model.yyy, etc., I would like to specify three thresholds, for example:

• com.company.Model (and subpackages): 80%
• com.company.Controllers (and subpackages): 30%
• com.company.Views (and subpackages): 0%

Seems it was requested by another user on stackoverflow.com: http://stackoverflow.com/questions/10747514/how-to-configure-jenkins-cobertura-plugin-to-monitor-specific-packages