Add GemFire Support

Fixes GH PR #148 and PR #308 implementing a GemFire Adapter to support
clustered HttpSessions in Spring Session.

* Resolve SGF-373 - Implement a Spring Session Adapter for GemFire backing
a HttpSession similar to the Redis support.
* Add Spring Session annotation to enable GemFire support with
@EnableGemFireHttpSession.
* Add extesion of SpringHttpSessionConfiguration to configure GemFire using
GemFireHttpSessionConfiguration.
* Add implementation of SessionRepository to access clustered, replicated
HttpSession state in GemFire with GemFireOperationsSessionRepository.
* Utilize GemFire Data Serialization framework to both replicate
HttpSession state information as well as handle deltas.
* Utilize GemFire OQL query to lookup arbitrary Session attributes by name,
and in particular the user authenticated principal name.
* Implment unit and integration tests, and in particular, tests for both
peer-to-peer (p2p) and client/server topologies.
* Set initial Spring Data GemFire version to 1.7.2.RELEASE, which depends
on Pivotal GemFire 8.1.0.
* Add documentation, Javadoc and samples along with additional Integration
Tests.

Fixes gh-148

samples/httpsession-gemfire-clientserver-xml/src/integration-test/groovy/sample/AttributeTests.groovy

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2002-2015 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 sample
+
+import geb.spock.*
+import sample.pages.HomePage;
+import spock.lang.Stepwise
+import pages.*
+
+/**
+ * Tests the CAS sample application using service tickets.
+ *
+ * @author Rob Winch
+ */
+@Stepwise
+class AttributeTests extends GebReportingSpec {
+	def 'first visit no attributes'() {
+		when:
+		to HomePage
+		then:
+		attributes.empty
+	}
+
+	def 'create attribute'() {
+		when:
+		createAttribute('a','b')
+		then:
+		attributes.size() == 1
+		attributes[0].name == 'a'
+		attributes[0].value == 'b'
+	}
+}

samples/httpsession-gemfire-clientserver-xml/src/integration-test/groovy/sample/pages/HomePage.groovy

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2002-2015 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 sample.pages
+
+import geb.*
+
+/**
+ * The home page
+ *
+ * @author Rob Winch
+ */
+class HomePage extends Page {
+	static url = ''
+	static at = { assert driver.title == 'Session Attributes'; true}
+	static content = {
+		form { $('form') }
+		submit { $('input[type=submit]') }
+		createAttribute(required:false) { name, value ->
+			form.attributeName = name
+			form.attributeValue = value
+			submit.click(HomePage)
+		}
+		attributes { moduleList AttributeRow, $("table tr").tail() }
+	}
+}
+class AttributeRow extends Module {
+	static content = {
+		cell { $("td", it) }
+		name { cell(0).text() }
+		value { cell(1).text() }
+	}
+}