@Path with regular expression containing parentheses does not resolve correctly

Currently the constructor for org.apache.cxf.jaxrs.model.URITemplate adds parentheses around the regex pattern.  However, if a user specifies a regex already containing parentheses then the URITemplate constructor will add additional parenthesis around the regex pattern.   This will result in the  Regex expression as being a group within another group and will cause the Matcher returned from Pattern.matcher() to contain duplicate values for this regex pattern.  As a result, the number of values will not match the number of variables. 

The URITemplate constructor should be changed to only add parentheses if they do not already exist.

I know this issue exists in version 3.3.6, but I suspect it may have existed in all previous versions as well.