luasocket: finish the makefile and fix shared libs

Note: mime.core requires socket.core, and have the same names
this is not compatible with Android, which try to load the same
lib on mime.core load.

So, add lua wrappers to the unique libs, liblua-socket and -mime

Add also new lib entries which doesnt use _core suffix :
example :

MIME_API int luaopen_mime(lua_State *L)
{
    return luaopen_mime_core(L);
}

Also reduce liblua-mime size, using the shared liblua-socket

Signed-off-by: Tanguy Pruvot <tanguy.pruvot@gmail.com>