showcase: updated version of RichFaces in readme (RF-13917)
Pom Updates

Added missing license information
Added missing xml tags
Fix maven schema location
Updated maven plugin versions
Updated maven compiler plugin and removed unnecessary source/target
settings (inherited)
Exclude unnecessary xalan from javaee-web-6.0 which is not readily
available in central and not required per build.
Add missing project.basedir or switch basedir to project.basedir as
later is deprecated.
Fall back to maven-war-plugin 2.4 due to bug

2.5 introduced filtering changes that causes build to break.  This is
fixed in unreleased version 3.0.  Therefore fallback this one only until
later date with comment as to why.
Updated .checkstyle.