Lots of minor fixes: mostly configuration issues.

Change to use std::tuple when available.
Add two new distributions: inverse gamma and inverse chi squared.


[SVN r65749]

libs/math

@@ -1 +1 @@
-Subproject commit 94f09f4ea22400363f442ef6c44c21810d644409
+Subproject commit 0bc7181e617451d21c13b5c08d9eec8a3f328de0