Fix an uninitialized member in a default-initialized split_iterator; Refs #9335

[SVN r86583]
Updated docs for is_sorted, etc. Refs #9367

[SVN r86741]
Fixed some file perms that got munged in the git conversion.
Changed parameters for the sequence-based versions of clamp from being passed by vaue to being passed by const &. Thanks to Martin Moene for the suggestion.
#ifdef out the four argument versions of is_permutation when we are compiling with C++14, since they're in the standard library
Rework the file layout and implementation of 'is_permutation' to match the various versions of the C++ standard. In particular, move the four iterator versions into the cxx14/ directory.
Merge from develop: clean up is_permutation; fix clamp interface, and merge fix for bug #9335 as well