STACK should delete the temporary plot files each time an image is created.
Updates to the docs.
Add the option to set the type of parentheses for matrices.
Ignore whitespace surrounding forbidden keywords in the input options.
Fix a bug in the question tests for single character which prevented the teacher entering a test case which has more than one character (and hence using the question variables).
Added a test case.
Updates to the docs.
Better error reporting.
Fix bug to subscripted expressions.
Minor changes:
 - add log-like functions to the trigop checks
 - update the sample course with the cart question
Added in matrixparens to the DB install
Make cosec an alias of csc.
Remove link to missing file.
Fixed failing unit test
Fix to issue #94
Display the answer provided by the teacher automatically as part of the general feedback.
Use the method correct_response from render.php.
Minor changes to language strings.
Merge branch 'master' into wipcasblocks

Conflicts:
	doc/en/Developer/Development_track.md
	settings.php
	tests/answertest_general_cas_test.php
	tests/castext_test.php
Minor changes to fix unit tests.