new client-side validation framework

add testing for ranlux and lagged_fibonacci engines
streamlined distribution instantiation


[SVN r15661]

libs/random

@@ -1 +1 @@
-Subproject commit cc07606e4853c449e24fc73c0dd7f8e780fcc809
+Subproject commit fccd5609fb62cad7ead4fc6c2c6a776e4fb38ad3