Fix lettergroups: Sort items to longest first.

Lang en-us: Use rhotic [3] in place of [@] when [r] follows.

Voice files: add attribute "fast-test" to experiment with faster talking speeds.


git-svn-id: https://espeak.svn.sourceforge.net/svnroot/espeak/trunk@212 d46cf337-b52f-0410-862d-fd96e6ae7743