Removed commented out-of-date code.

(This became redundant due to late changes in the spec.)
Some general gardening on JQTI+:

* Removed commented-out code
* Pruned more landfill JavaDoc
* Improved some doc comments

No functional changes here.
Merged ContainerBlock into ForeignElement
Completed interface impls for InfoControl
JQTI+: added stylesheet assn rubricBlock

This was a late addition to the spec. Note that QTIWorks Engine's
renderingcurrently does nothing useful with this - it's non-trivial to
implement.
Further tidying to JQTI+:

* Deprecated getChildren() methods for navigating the QTI class
hierarchy so that they consistently use names based on the content
class that will be returend.
* Some minor fixes to interface impls of content classes
* Further minor JavaDoc improvements.
Changed version back to 1.0-SNAPSHOT
Fixed bug in author debug view.

the qw:formatNodeKey(.) XPath function wasn't handling multiple
node instances correctly.
Improved logging of candidate session explosions
Fix to logic in TestPlan regarding node indices

There was a logic mismatch in the meaning of "global index", leading
to wrong behaviour in some ordered/selection questions. Logic now fixed.
Fixed regression in test item feedback rendering

An error was introduced in the XPath expression for determining
whether item feedback should be fixed. This is now fixed by checking
against 1.0-M4a
Ready for 1.0-DEV34
Set version back to 1.0-SNAPSHOT
MathAssess: better error handling

I wasn't intercepting all possible classes of Exceptions that could
come from Maxima, which meant questions with dodgy Maxima would cause
exploded sessions. All possible Exceptions are now converted to runtime
errors, which should be more helpful for users.
Fixed bug in transient data deletion process.
Fix to simple REST: success now returns 303
Validation now checks for adpative + simult.

Adaptive items can't work correctly in a testPart having
simulataneous submission mode. The validator now checks for this
and issues a warning.
Removed duplicate validation warning message
Tiny tweak to new runtime error messages in MA Ext
Ready for 1.0-beta2