Merge pull request #4411 from wting/4203_rename_memcpy

Rename memcpy, memmove, memset

diff --cc src/libcore/io.rs
Simple merge

diff --cc src/libcore/ptr.rs
Simple merge

diff --cc src/libcore/str.rs
Simple merge

diff --cc src/libcore/vec.rs
Simple merge

diff --cc src/libstd/net_tcp.rs
Simple merge