doc(selector): add the ":contains()" pseudo-selector

see dartbug.com/16422

Closes #639

Author: vicb

lib/core/directive.dart

@@ -9,6 +9,7 @@ abstract class NgAnnotation {
    * * `.class` limit to an element with a given class.
    * * `[attribute]` limit to an element with a given attribute name.
    * * `[attribute=value]` limit to an element with a given attribute and value.
+   * * `:contains(/abc/)` limit to an element which contains the given text.
    *
    *
    * Example: `input[type=checkbox][ng-model]`

lib/core_dom/selector.dart

@@ -22,6 +22,7 @@ part of angular.core.dom;
  *   [attribute]
  *   [attribute=value]
  *   element[attribute1][attribute2=value]
+ *   :contains(/abc/)
  * </pre>
  *
  *

test/core_dom/selector_spec.dart

@@ -44,23 +44,23 @@ main() {
     beforeEach(() => log = []);
     beforeEach(module((Module module) {
       module
-        ..type(_BElement)
-        ..type(_BClass)
-        ..type(_DirectiveAttr)
-        ..type(_WildcardDirectiveAttr)
-        ..type(_DirectiveFooAttr)
-        ..type(_BElementDirectiveAttr)
-        ..type(_DirectiveValueAttr)
-        ..type(_BElementDirectiveValue)
-        ..type(_ContainsAbc)
-        ..type(_AttributeContainsXyz)
-        ..type(_Component)
-        ..type(_Attribute)
-        ..type(_Structural)
-        ..type(_IgnoreChildren)
-        ..type(_TwoDirectives)
-        ..type(_OneOfTwoDirectives)
-        ..type(_TwoOfTwoDirectives);
+          ..type(_BElement)
+          ..type(_BClass)
+          ..type(_DirectiveAttr)
+          ..type(_WildcardDirectiveAttr)
+          ..type(_DirectiveFooAttr)
+          ..type(_BElementDirectiveAttr)
+          ..type(_DirectiveValueAttr)
+          ..type(_BElementDirectiveValue)
+          ..type(_ContainsAbc)
+          ..type(_AttributeContainsXyz)
+          ..type(_Component)
+          ..type(_Attribute)
+          ..type(_Structural)
+          ..type(_IgnoreChildren)
+          ..type(_TwoDirectives)
+          ..type(_OneOfTwoDirectives)
+          ..type(_TwoOfTwoDirectives);
     }));
     beforeEach(inject((DirectiveMap directives) {
       selector = directives.selector;