Evas textblock: Added support for default tags.
Evas textblock: Added support for default tags.

This is useful for defining default tags that can be overridden by style.
For example <b> and <i>.

git-svn-id: 24a995eca3b83137dd7eab3408044d7832e202f7@66190 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33

antognolli/Evas,antognolli/Evas,antognolli/Evas,antognolli/Evas