Provide support for documenting path parameters

This commit adds support for documenting a request's path parameters.
For example:

mockMvc.perform(
		get("/locations/{latitude}/{longitude}", 51.5072, 0.1275))
			.andExpect(status().isOk())
			.andDo(document("locations").withPathParameters(
					parameterWithName("latitude")
							.description("The location's latitude"),
					parameterWithName("longitude")
							.description("The location's longitude")
			));

Closes gh-86

docs/src/test/java/com/example/PathParameters.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2014-2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example;
+
+import static org.springframework.restdocs.RestDocumentation.document;
+import static org.springframework.restdocs.request.RequestDocumentation.parameterWithName;
+import static org.springframework.restdocs.RestDocumentationRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import org.springframework.test.web.servlet.MockMvc;
+
+public class PathParameters {
+
+	private MockMvc mockMvc;
+
+	public void pathParameters() throws Exception {
+		// tag::path-parameters[]
+		this.mockMvc.perform(get("/locations/{latitude}/{longitude}", 51.5072, 0.1275)) // <1>
+			.andExpect(status().isOk())
+			.andDo(document("locations").withPathParameters( // <2>
+					parameterWithName("latitude").description("The location's latitude"), // <3>
+					parameterWithName("longitude").description("The location's longitude") // <4>
+			));
+		// end::path-parameters[]
+	}
+
+}