Add a preCondition callback to SuccessCriteria object

The preCondition callback will be executed during the call to
SuccessCriteria.registerTests() and replace the testCollection sent with an
empty testCollection.
Add a preCondition callback to SuccessCriteria object

The preCondition callback will be executed during the call to
SuccessCriteria.registerTests() and replace the testCollection sent with an
empty testCollection.
Merge pull request #253 from theodoreb/preEvaluator

Add a preEvaluator callback to SuccessCriteria object
Changed all instances of inapplicable to notApplicable to remain internally consistent. We will eventually want to change these to inapplicable to use the default EARL status states, but since EARL itself is not very clear about this, we will stick with the current internal patterns for now.
Dutch translations
Small fixes to the preEvaluation functions and better integration with the two existing Success Criteria.
some closing quotes added

Signed-off-by: Hanno Lans <hanno@hannolans.nl>
one more quote typo

Signed-off-by: Hanno Lans <hanno@hannolans.nl>
and many more small typos

some tabs, som quotes, some spaces, some points.

Signed-off-by: Hanno Lans <hanno@hannolans.nl>
Refactor color code to limit jQuery css queries and faster element selection for #259
For #259 replace slow contrast test with faster test.
Use strict, helps a little with #259
Don't run unit tests twice when using command line
Use native selector
Optimize getTextContents function to avoid a full element clone
Refactor languageDirAttributeIsUsed test to limit jQuery duplication and optimize some code paths
Refactor aAdjacentWithSameResourceShouldBeCombined code for faster execution
Clearner size() implementation
Merge pull request #257 from KINGgemeenten/translations

Dutch translations
Add Success Criteria 1.4.2