Updating to Maven 3.1.x or better

1) Use Maven 3.1.1 or better
2) Updated third party dependencies to latest (jdk6 versions) as
   readily available in maven central.
3) Updated property settings annotation in code based on maven 3.1.x
changes
4) Minor cleanup (removing unused imports deleting duplicate blank
lines)
5) Made compression recursive so additional properties are not required
to get this working.  This matches how yui compressor maven task works
as well as ant based versions of yui compressor and htmlcompressor.
This fixes one noted issue on github.  Items are picked up from
src/main/resource and placed in proper place under target/classes.
6) Updated readme to match recursive nature of project now.
7) Added old target locations to the mojo tests to ensure this test data
doesn't get picked up in final jar build.
8) Fixed xsd location for maven