Updated README and CHANGELOG for v0.3 release.

CHANGELOG.md

@@ -3,6 +3,20 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+###  [v0.3](https://github.com/fpagliughi/rust-industrial-io/compare/v0.2..v0.3) - 2021-05-26
+
+
+- Support for _libiio_ v0.21
+- Updated error handling:
+    - Support for `std::error`
+    - Implementation changed to use `thiserror` (from *error_chain*)
+    - Specific types defined for common errors intead of just string descriptions (`WrongDataType`, `BadReturnSize`, `InvalidIndex,` etc)
+- New device capabilities:
+    - _remove_trigger()_
+    - _is_buffer_capable()_
+- New utility app: _riio_stop_all_
+
+
 ## [v0.2](https://github.com/fpagliughi/rust-industrial-io/compare/v0.1..v0.2) - 2019-12-29
 
 - Support for libiio v0.18

README.md

@@ -14,7 +14,7 @@ industrial-io = "0.3"
 ```
 
 
-## Pre-release notes
+## Pre-release Note
 
 This is a pre-release verion of the crate. The API is stabilizing, but is still under active development and may change before a final release.
 
@@ -32,7 +32,7 @@ To keep up with the latest announcements for this project, follow:
 
 **Twitter:**  [@fmpagliughi](https://twitter.com/fmpagliughi)
 
-### Unreleased Features in This Branch
+### New in v0.3
 
 - Support for _libiio_ v0.21
 - Updated error handling:
@@ -44,17 +44,6 @@ To keep up with the latest announcements for this project, follow:
     - _is_buffer_capable()_
 - New utility app: _riio_stop_all_
 
-### New in v0.2
-
-- Support for libiio v0.18
-- Further implementation of _libiio_ functions for contexts, devices, channels, etc.
-- Functions to read and write buffers, with and without conversions, and to convert individual samples to and from hardware format.
-- [Breaking] Removed previous `ChannelType` for Input/Output as it conflicted with the library's channel types of `Voltage`, `Current`, `Power`, etc, and implemented the library type.
-- Contexts have a ref-counted "inner" representation using _Rc<>_, and can be "cloned" quickly by incrementing the count. (Thanks, @skrap!)
- - Devices carry a cloned reference to the context that created them, thus keeping the context alive until the last device using it gets dropped.
- - Some clippy-recommended lints.
- - Example app to collect and process data a buffer at a time, with conversions.
-
 ## Testing the Crate
 
 A great thing about the user-space IIO libraries is that, if you're developing on a fairly recent Linux host, you can start experimenting without having to do development on a board. You can run the IIO server daemon on an embedded board, and then use this crate to communicate with it over a network connection. When your application is working, you can then compile it for the target board, test it natively, and deploy.