Code quality and Metrics Plugins

This pull requests adds configurations for;

1. Checkstyle
2. PMD
3. Findbug
4. Cobertura

They have been configured in a profile called codequality that can be invoked separately from the usual build.
The config files "checkstyle.xml" and "pmd.xml" are in the root folder, wouldn't it be easier if they were inside the RapidFTR-Android folder, since we don't want it to run for anything else? So that we won't need any custom variables, we can just use `basedir`?