Crates io (#76)

* crates re-organisation

* fixed typo in layout & added test for vmp_apply

* updated dependencies

poulpy-hal/src/layouts/serialization.rs

@@ -0,0 +1,9 @@
+use std::io::{Read, Result, Write};
+
+pub trait WriterTo {
+    fn write_to<W: Write>(&self, writer: &mut W) -> Result<()>;
+}
+
+pub trait ReaderFrom {
+    fn read_from<R: Read>(&mut self, reader: &mut R) -> Result<()>;
+}