Add a prospective LESS error reporting test
Introduce - [LRBuild addOperationResult:forTarget:key:]
Fail tests when compilation fails
Actually compare the error messages in error tests
Add test: less_error_imported (passes, but has duplicate errors)
Add test: coffeescript_error (fails)
Fix (Iced)CoffeeScript error parsing
Add tests for all remaining compilers
Pull error manifest changes for Eco, HAML and SLIM
Merge branch 'feature/add-error-reporting-tests' into develop