Add underline attribute

git-svn-id: https://svn.apache.org/repos/asf/flex/sdk/branches/develop@1434934 13f79535-47bb-0310-9956-ffa450edef68
Don't put non-essential stuff in the bitmap

git-svn-id: https://svn.apache.org/repos/asf/flex/sdk/branches/develop@1434935 13f79535-47bb-0310-9956-ffa450edef68