Update docs with Linux performance results.

Fix distributions.cpp so it's DCDFLIB testing code is gcc-compatible.

[SVN r56925]

libs/math

@@ -1 +1 @@
-Subproject commit 66f2eed7dcdbf8b826b1a0bc16810b8ff0af2afa
+Subproject commit 6227f67d75deed3d5617cdacaea7b3bff62920b9