Adds a variable declaration to the current scope; if the symbol was
previously "unresolved" it is removed from the unresolved list

@param name {String} the name of the variabvle being declared
@param valueName {String} the value to assign to the variable
function(name, valueName) {
      if (this.__scope.vars[name] === undefined) {
        this.__scope.vars[name] = valueName || true;
        var unresolved = this.__scope.unresolved;
        delete unresolved[name];
        var re = new RegExp(name + "\\.");
        for (var tmp in unresolved) {
          if (re.test(tmp)) {
            delete unresolved[tmp];
          }
        }
      }
    }