Renamed stite.xml assembly descriptor to static-resources.xml.

Switched to directory style of assembly to ease upload using Maven Wagon plugin.
Adapted assembly and Wagon plugin to automate distribution upload.

Predefined necessary properties. Declared Wagon plugin to upload static resources and schemas. Declared additional ant run execution to upload distribution ZIP to S3. Disable standard deploy plugin. Updated read me accordingly.
Added profiles to transparently activate release and milestone distribution.
Upgraded to Spring 3.1.4.RELEASE.
Removed the need to define a ${schema.key}.