php-peg library. For the PEG-parsing.

Probably someone knows a better place for it, maybe Moodle even has a better way for this.
And then that php-peg thing again... as I failed the submodule thing.
Conditionally evaluated casstrings. These make it possible to evaluate if-blocks in single pass.
PEG-parser based new castext-processor. Requires valid XML syntax in castext.
The initial set of new blocks for the new castext parser.
Went trough the specs and noticed something missing, now LaTeX-output wraps everything in {}.
New attempt at blocks now with [[ block param='blaah' ]]...[[/ block ]] syntax. No DOM-parsers.

TODO: the PEG-parser should parse nested blocks instead of just lexing as it does now. But as I could not figure out why it does not work I did my own tricks to build a parse tree.

Expect unit-tests soon.
Some tests for the parser, not for actuall castext processing.
Fixing some merge issues...
Merge remote-tracking branch 'upstream/master'

Conflicts:
	stack/cas/cassession.class.php
Missed something in the merge, now with that $cleanlabel.
Empty-blocks added to the parser [[ block a='b' /]].

Unit tests for the parsers inner logic.
Why did I remove that array_reverse?
Access all of the parameters of a block.
Tests and fixes to various issues with them.
foreach block and some fixes to make it work. Also define-block and tests.
Merge branch 'master' of github.com:maths/moodle-qtype_stack
Some strings for the healtcheck.
Nested foreach test-case.
Some documentation updates.
Merge branch 'master' of github.com:maths/moodle-qtype_stack

Conflicts:
	lang/en/qtype_stack.php