implementation component.  So no real functional code changes in this commit.

--HG--
rename : dlib/sockstreambuf/sockstreambuf_kernel_2.cpp => dlib/sockstreambuf/sockstreambuf.cpp
rename : dlib/sockstreambuf/sockstreambuf_kernel_2.h => dlib/sockstreambuf/sockstreambuf.h
rename : dlib/sockstreambuf/sockstreambuf_kernel_abstract.h => dlib/sockstreambuf/sockstreambuf_abstract.h
rename : dlib/sockstreambuf/sockstreambuf_kernel_1.cpp => dlib/sockstreambuf/sockstreambuf_unbuffered.cpp
rename : dlib/sockstreambuf/sockstreambuf_kernel_1.h => dlib/sockstreambuf/sockstreambuf_unbuffered.h