Add an escape attribute to h:messages and h:message like in h:outputText

I want to output an HTML link as part of my error message, but can't because the
HTML is escaped by h:messages. I searched Google for a workaround and found
many people have the same problem. There have even been tickets created against
JSF RI and MyFaces years ago.

[https://javaserverfaces.dev.java.net/issues/show_bug.cgi?id=746](https://javaserverfaces.dev.java.net/issues/show_bug.cgi?id=746)
[http://issues.apache.org/jira/browse/MYFACES-155](http://issues.apache.org/jira/browse/MYFACES-155)
#### Environment
Operating System: All
Platform: All
#### Affected Versions
[2.0]

Start by reading the h:messages and h:message component definitions and comparing their escaping behavior with h:outputText. Locate the relevant component or rendering tests before making changes; done means both message tags support the requested escape control, with HTML links renderable when escaping is disabled and escaping retained by default.

Written by the indexing model from the issue text.