Merge branch 'dlopen_dlclose_dlsym' into 'master'

src/c_vec.rs

src/header/dlfcn/mod.rs

src/header/netdb/mod.rs

src/ld_so/callbacks.rs

src/ld_so/library.rs

src/ld_so/linker.rs

src/ld_so/mod.rs

src/ld_so/start.rs

src/platform/allocator/dlmalloc.rs

src/platform/redox/epoll.rs

src/platform/redox/socket.rs

src/start.rs