Ensure source folders appear first in the classpath list.

After running the other Classpath Configuration classes the source folders
are out of sequence, causing all sorts of problems looking up source. This
is an attempt to re-order the classpaths.  It hasn't yet been tied into the
code, but here for code review and comment.
How do we know which order things should be added then.   The current implementation goes by maven naming standards.   I can add code to add all the others ahead of the non-source folder items.

If main/java isn't first and you are debugging from another project, the source lookup fails.   Also, the android-maven-plugin handles generation of the R files and it puts them in a particular directory, so we can look in there and grab the root folder for each of the generated files.