Add css node declaration object to the GssError for better error reporting.

[a701440]

The code in CSS validation does not send failing CSS node to the error manager. Having the node object can provide more information for richer error reporting (i.e. print parent node content, etc.)

Current code in places like processDeclaration:

errorManager.report(new GssError(ERROR_STR + declaration, location));

Change to something like:

errorManager.report(new GssError(ERROR_STR + declaration, location, declaration));