Add new RMW storage implementation

Despite it looks little bit low-level but it works well with unaligned access.
I/O operations optimized by splitting it to stages:

- Not aligned start
- Aligned middle
- Not Aligned end

Each stage may or may not be needed depending from memory offset and data
length.

Also the data checked to determine that erase and/or write needed or not.

Author: katyo

src/iter.rs

@@ -8,17 +8,9 @@
 #![deny(missing_docs)]
 #![deny(unsafe_code)]
 
-/// Currently contains [`OverlapIterator`]
-pub mod iter;
 /// Technology specific traits for NOR Flashes
 pub mod nor_flash;
 
-/// A region denotes a contiguous piece of memory between two addresses.
-pub trait Region {
-	/// Check if `address` is contained in the region of `Self`
-	fn contains(&self, address: u32) -> bool;
-}
-
 /// Transparent read only storage trait
 pub trait ReadStorage {
 	/// An enumeration of storage errors