issue #657 - downloadform revamp

- Using spring internals to access the database
- introducing unit tests
XmlLint'ing downloadform/pom.xml
downloadform - Fixing dependencies (#657)

Using apache commons dbcp pool for database access (the previous try
with spring classes was not pooling)
Major revamp of downloadform webapp (#657)

- Preparing some tests
- Fixing a potential race condition issue with servlet requests
  (exporting requests parameters to a new object called DownloadQuery)
- Using dbcp pool for connection pooling to the db
- Rewrite / code cleaning on the controllers
downloadform - major revamp (#657)

- Adding skeleton tests for missing controllers
- Finishing tests on DataUsage
downloadform - Adding a test on DataUsage controller (#657)

Ensures that an empty array is returned if no results from the database.
downloadform revamp - Finishing testsuite (#657)

- Leveraging test suite to 94% of line coverage
- fixing / refactoring some last things

TODO: Still need to test at runtime
downloadform - debugging at runtime

Avoid getting db connection without releasing them, reusing connections
across the controller.
Merge pull request #683 from pmauduit/issue-657

downloadform - revamp of the webapp