Spring update

This pull request includes an update to our Spring dependencies as well as a few other goodies:

* Moves source/target to 1.7 (from 1.6)
* A fix to the HSQLDB DDL statements
* Adds jetty-maven-plugin so we don't have to install Tomcat (6!) separately any more
* Drops the profiles for running Tomcat 6's JSPC task while we are at it
* scheduling-assistant-SAMPLE.properties is now scheduling-assistant-default.properties and is loaded by default (scheduling-assistant.properties will still override)

Many of the sub-modules had overriding (and sometimes duplicating) versions for dependencies, those are all gone. The dependencyManagement block in the parent pom has had a major cleanup. Gone are properties for every dependency version; we keep only the properties where we reference a particular version in multiple modules.