Change to ZIP/XML import logic

Fixes bug #28. We no longer check the MIME type of ZIP content
and instead try to expand it and succeed if a valid ZIP entry is
found. Some changes have been made to the API to accommodate this
safely.
Ready for 1.0-M4a.

(This cherry-picks commit 99b5db5 from the master branch, which
rewrote the CP-handling code to make it less fussy.)
Cherry-picked new MathJax URL from master branch
Patch release (1.0-M4b) to use new MathJax SSL CDN

(The old SSN CDN has gone offline, so I've cherry-picked the
new URL and the upgrade to MathJax 2.1 from the master branch.)
Set version back to 1.0-SNAPSHOT
Removed some redundant stuff from JQTI+
Some minor tidying of qtiworks-engine module
Added LoadModifyAndSaveQtiExample code example
Fixed 3 double-escaped EL functions
EL fn for displaying AssPckg file name removed

This became redundant after recent changes to the
AssessmentPackage entity, so simpler to get rid.
URL of my hosted QTIWorks installs updated.

The final 1.0 release will use webapps.ph.ed.ac.uk/... instead of
www2.ph.ed.ac.uk/... in future. The old address will continue to be
supported so that existing LTI links don't break; though visits to
the static parts of the site will redirect to the new domain if
not there already.
Tidied up the anonymous MVC URLs a bit

* The anonymous MVC now answers to /anonymous instead of /web/anonymous
* The URL of the samples list has been somplified.
* I've added a temporary legacy MVC to cater for Uniqurate, which will
use the old address for now.
Removed unused JSON stuff
Added very simple REST-like assessment runner
Tidied up legacy UQ controller
Ack - reinstanted JSON stuff for candidate MVC

I forgot that this was required for the mathEntryInteraction
feedback. So restored now, but only for the candidate MVC
Updated Spring to 3.2.4 and Hibernate to 4.1.12
Minor fixes and tweaks to data purge process.

There were annoying Hibernate session/TX issues when running
in the webapp. This should fix, but lack of test suite makes it
hard to be sure so I'll have to keep an eye on things when this
goes into production.
Renamed m4-to-m5.sql -> m4-to-beta1.sql

(Next release will be BETA1, rather than M5.)
Fixed some bugs in the M4->BETA1 schema migration

(These were found after running on a copy of the live data in
production.)