Moving to standard directory layout

This seems to be a big change - lots of file renames at least.

This removes testinputs.dir and testsrcs.dir system properties using just the relative filepaths instead. I've tested this change on Linux (from terminal with maven, Eclipse, Netbeans and Idea - in Idea this issue prevents to run tests normally by default run configuration - http://youtrack.jetbrains.com/issue/IDEA-121076 - you can create custom JUnit configuration for all tests in src/test/java folder). Also I tested this change on Windows - from terminal with maven and from Eclipse.

Another big change - is that messages are moved to src/main/resources - so in the java-sources folder only java sources are left.

As a side note - what bothers be about checkstyle - is that it requires java.io.File to run checks - this class can not always be available (GAE and other restricted environments) and it is too low-level for various IDE integration (consider emerging cloud IDEs). What about moving to some abstract Stream - so tests can run on Test.class.getResourceAsStream() input?