COMP: Replace memcpy calls with std::copy

There are (before this patch) 88 calls to memcpy
in the ITK source code. In nearly every case it
can be replaced with std::copy or std::copy_n.
These template functions preserves strict
C++ type checking, and use proper object copy semantics.

In tests done by various people (found by google search), most
implementations of std::copy perform as well or better than
memcpy, so there is no performance reason to stick with the
low level C function to copy data.

std::copy_n isn't apparently supported by all compilers &
STL implementations (though it's part of TR1 & C++11), so
a compile test is added for copy_n and an implementation of
it (based on std::copy) for the case of copy_n being unavailable

Change-Id: Ica4423e348973f81eabffb548aa7f383f7ba2831
Merge topic 'ReplaceMemcpyWStdCopy'

da5e1b3 COMP: Replace memcpy calls with std::copy