* Bind data using headers as source [#1866](https://github.com/labstack/echo/pull/1866)
* Adds JWTConfig.ParseTokenFunc to JWT middleware to allow different libraries implementing JWT parsing. [#1887](https://github.com/labstack/echo/pull/1887)
* Adding tests for Echo#Host [#1895](https://github.com/labstack/echo/pull/1895)
* Adds RequestIDHandler function to RequestID middleware [#1898](https://github.com/labstack/echo/pull/1898)
* Allow for custom JSON encoding implementations [#1880](https://github.com/labstack/echo/pull/1880)
* Route matching has improvements for following cases:
1. Correctly match routes with parameter part as last part of route (with trailing backslash)
2. Considering handlers when resolving routes and search for matching http method handler
* Echo minimal Go version is now 1.13.
**Fixes**
* When url ends with slash first param route is the match [#1804](https://github.com/labstack/echo/pull/1812)
* Router should check if node is suitable as matching route by path+method and if not then continue search in tree [#1808](https://github.com/labstack/echo/issues/1808)
* Fix timeout middleware not writing response correctly when handler panics [#1864](https://github.com/labstack/echo/pull/1864)
* Fix binder not working with embedded pointer structs [#1861](https://github.com/labstack/echo/pull/1861)
* Add Go 1.16 to CI and drop 1.12 specific code [#1850](https://github.com/labstack/echo/pull/1850)
**Enhancements**
* Make KeyFunc public in JWT middleware [#1756](https://github.com/labstack/echo/pull/1756)
* Add support for optional filesystem to the static middleware [#1797](https://github.com/labstack/echo/pull/1797)
* Add a custom error handler to key-auth middleware [#1847](https://github.com/labstack/echo/pull/1847)
* Allow JWT token to be looked up from multiple sources [#1845](https://github.com/labstack/echo/pull/1845)
The behaviour for binding data has been reworked for compatibility with echo before v4.1.11 by
enforcing `explicit tagging` for processing parameters. This **may break** your code if you
expect combined handling of query/path/form params.
Please see the updated documentation for [request](https://echo.labstack.com/guide/request) and [binding](https://echo.labstack.com/guide/request)
The handling for rewrite rules has been slightly adjusted to expand `*` to a non-greedy `(.*?)` capture group. This is only relevant if multiple asterisks are used in your rules.
Please see [rewrite](https://echo.labstack.com/middleware/rewrite) and [proxy](https://echo.labstack.com/middleware/proxy) for details.
**Security**
* Fix directory traversal vulnerability for Windows (#1718, little-cui)
* Fix open redirect vulnerability with trailing slash (#1771,#1775 aldas,GeoffreyFrogeye)
**Enhancements**
* Add Echo#ListenerNetwork as configuration (#1667, pafuent)
* Add ability to change the status code using response beforeFuncs (#1706, RashadAnsari)
* Echo server startup to allow data race free access to listener address
* Binder: Restore pre v4.1.11 behaviour for c.Bind() to use query params only for GET or DELETE methods (#1727, aldas)
* Binder: Add separate methods to bind only query params, path params or request body (#1681, aldas)
* Binder: New fluent binder for query/path/form parameter binding (#1717, #1736, aldas)
* Router: Performance improvements for missed routes (#1689, pafuent)
* Router: Improve performance for Real-IP detection using IndexByte instead of Split (#1640, imxyb)
* Middleware: Support real regex rules for rewrite and proxy middleware (#1767)
* Middleware: New rate limiting middleware (#1724, iambenkay)
* Middleware: New timeout middleware implementation for go1.13+ (#1743, )
* Middleware: Allow regex pattern for CORS middleware (#1623, KlotzAndrew)
