Added missing language strings for Coderunner cache. (#221)

lang/en/qtype_coderunner.php

@@ -1344,4 +1344,6 @@ function should be applied, e.g. <code>{{STUDENT_ANSWER | e(\'py\')}}</code> is
 
 $string['xmlcoderunnerformaterror'] = 'XML format error in coderunner question';
 $string['enablegradecache'] = 'Enable reading/writing of job,result pairs from/to the Coderunner grading cache.';
+$string['coderunner_grading_cache'] = 'Caches grading results so we can avoid going to Jobe so often.';
+$string['cachedef_coderunner_grading_cache'] = 'Caches grading results so we can avoid going to Jobe so often.';
 $string['enablegradecache_desc'] = 'Experimental. The cache is a local Moodle cache (currently file cache) to store results of grading questions. Mainly to speed up regrading by using cached results for jobe runs where the same jobe submission has already been graded. Currently WS jobs (eg, try-it boxes and scratchpad runs) will never be cached. NOTE: If you turn off grade caching then it is usually good to empty the Coderunner grade cache before you turn it on again so you have a known state for the cache. You should also clear the cache if you change the Jobe back-end (eg, installing a new version of Python there) as results may now differ from what is in the cache.';