Merge Algorithm changes to release; hex code cleanups; gather iterator requirements; copy_while and copy_until interface changes

[SVN r83347]

libs/algorithm

@@ -1 +1 @@
-Subproject commit 2381d0bdace1a6f665738f410db83a181ae95187
+Subproject commit 63da6f571331a14f8ef2fe7bdafd209a3b107f4e