SGF-408 - Provide support in the SDG XML namespace to load a pre-defined data set using GemFire Snapshot Service for development and testing purposes.

Refactored the ServiceSnapshotFactoryBean class to handle ZIP and JAR files as input sources on GemFire Cache data imports.
Added additional unit tests for SnapshotServiceFactoryBean to improve coverage along with a basic integration test covering import and export.
Fixed bugs in the SnapshotServiceParser and the XSD.
Moved the iterable(:Enumeration) and iterable(:Iterator) methods from the test CollectionUtils class to the 'official' CollectionUtils class.
(cherry picked from commit b47884c88c52b612aff6b8aa01fc0994ac42095c)

Signed-off-by: John Blum <jblum@pivotal.io>

src/test/resources/org/springframework/data/gemfire/SnapshotServiceImportExportIntegrationTest-context.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	   xmlns:gfe="http://www.springframework.org/schema/gemfire"
+	   xmlns:gfe-data="http://www.springframework.org/schema/data/gemfire"
+	   xmlns:util="http://www.springframework.org/schema/util"
+	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	   xsi:schemaLocation="
+		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
+        http://www.springframework.org/schema/gemfire http://www.springframework.org/schema/gemfire/spring-gemfire.xsd
+        http://www.springframework.org/schema/data/gemfire http://www.springframework.org/schema/data/gemfire/spring-data-gemfire.xsd
+        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd
+">
+
+	<util:properties id="gemfireProperties">
+		<prop key="name">SnapshotServiceImportExportIntegrationTest</prop>
+		<prop key="mcast-port">0</prop>
+		<prop key="log-level">warning</prop>
+	</util:properties>
+
+	<gfe:cache properties-ref="gemfireProperties"/>
+
+	<gfe:partitioned-region id="People" persistent="false"/>
+
+	<gfe-data:snapshot-service id="peopleSnapshotService" region-ref="People">
+		<gfe-data:import-snapshot location="gemfire/snapshots/import/people.snapshot"/>
+		<gfe-data:export-snapshot location="gemfire/snapshots/export/people.snapshot" format="GEMFIRE"/>
+	</gfe-data:snapshot-service>
+
+</beans>