Prefix function names with spring-

* Add `spring-` prefix to function names

Fixes: #9

This commit renames each sub-module in the common, consumer, function
and supplier groups with a prefix of `spring-`.

* Update README.adoc links to new prefixed names

function/spring-http-request-function/README.adoc

@@ -0,0 +1,32 @@
+# HTTP Request Function
+
+This module provides an HTTP request function that can be reused and composed in other applications.
+The `Function` uses the reactive `WebClient` from `Spring WebFlux` and is implemented as a `java.util.function.Function`.
+This function gives you a reactive stream of `ResponseEntity` given a stream of request messages as the function a signature of `Function<Message<?>,ResponseEntity>`.
+Users have to subscribe to the returned `Flux` to receive the data.
+
+## Beans for injection
+
+You can import the `HttpRequestFunction` configuration in a Spring Boot application and then inject the following bean.
+
+`httpRequestFunction`
+
+You may inject this as `HttpRequestFunction`.
+
+You can use `httpRequestFunction` as a qualifier when injecting.
+
+Once injected, you can use the `apply` method of the `Function` to invoke it and then subscribe to the returned `Flux`.
+
+## Configuration Options
+
+All configuration properties are prefixed with `http.request`.
+
+For more information on the various options available, please see link:src/main/java/org/springframework/cloud/fn/http/request/HttpRequestFunctionProperties.java[HttpRequestFunctionProperties.java]
+
+## Examples
+
+See this link:src/test/java/org/springframework/cloud/fn/http/request/HttpRequestFunctionApplicationTests.java[test suite] for examples of how this function is used.
+
+## Other usage
+
+See this link:../../../applications/processor/http-request-processor/README.adoc[README] where this function is used to create a Spring Cloud Stream application to process HTTP requests.