Recognise 'debug' sandbox param, and set debug field of runspec accordingly. Allows per-question debugging on jobe server.
Fix bug in javascript processing of question types without combinator templates.
Add 'sourcefilename' option to sandbox params to allow a question to specify the name of the source file.
Modify Java_Class question type to replace 'public class' with just 'class' so students do not need to be instructed to write non-public classes. [A bit of a hack but should cause fewer problems that requiring students to write non-public classes always.]
Documentation updates.