Merge from trunk:

* Update documentation of Boost.Function and add info about rvalues (fixes #8505)

[SVN r84788]

libs/function

@@ -1 +1 @@
-Subproject commit 62cce2aaaf1484808edf5222dda3df2581fba56b
+Subproject commit 9245ac2a8f0427cb5b7461e2f90aa2270f519004