Set correct Subversion properties: mime-type, eol-style and keywords. We need to handle these files in a special  way because they use UTF-16 encoding. By default Subversion detects these as being binary.

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1525209 13f79535-47bb-0310-9956-ffa450edef68