XD-1895 - Use Boot plugin and IO Platform for versions where possible

Before:

```
ext {
activemqVersion = '5.6.0'
args4jVersion = '2.0.16'
commonsBeanUtilsVersion = '1.6'
commonsPool2Version = '2.0'
commonsCollectionsVersion = '3.2'
commonsIoVersion = '2.4'
curatorVersion = '2.5.0'
equalsverifierVersion = '1.1.3'
ftpServerVersion = '1.0.6'
greenmailVersion = '1.3.1b'
groovyVersion = '2.3.2'
guavaVersion = '14.0.1'
h2Version = '1.3.172'
hamcrestDateVersion = '0.9.3'
hamcrestVersion = '1.3'
hibernateValidatorVersion = '4.3.1.Final'
hsqldbVersion = '2.3.0'
jackson1Version = '1.9.13'
jacksonVersion = '2.3.1'
javaxMailVersion = '1.5.0'
jcloudsVersion = '1.7.0'
jedisVersion = '2.4.1'
jodaTimeVersion = '2.1'
jolokiaVersion = '1.1.5'
jsonPathVersion = '0.8.1'
junitVersion = '4.11'
kryoVersion = '2.22'
log4jVersion = '1.2.17'
mockitoVersion = '1.9.5'
mysqlVersion = '5.1.23'
nettyVersion = '3.6.6.Final'
postgresqlVersion = '9.2-1002-jdbc4'
reactorVersion = '1.1.0.RELEASE'
reactorSpringVersion = '1.1.0.RELEASE'
slf4jVersion = '1.7.6'
snakeYamlVersion = '1.12'
snappyVersion = '1.1.0'
splunkVersion = '1.2.0'
springAmqpVersion = '1.3.4.RELEASE'
springBatchAdminMgrVersion = '1.3.0.M1'
springBatchVersion = '3.0.1.BUILD-SNAPSHOT'
springBootVersion = '1.1.2.BUILD-SNAPSHOT'
springCloudVersion = '0.9.2'
springDataCommonsVersion = '1.8.0.RELEASE'
springDataGemfireVersion = '1.4.0.RELEASE'
springDataHadoopBase = '2.0.0.RELEASE'
springDataHadoopVersion = "${springDataHadoopBase}"
springDataMongoVersion = '1.5.0.RELEASE'
springDataRedisVersion = '1.2.1.RELEASE'
springHATEOASVersion = '0.9.0.RELEASE'
springIntegrationSplunkVersion = '1.1.0.M2'
springIntegrationVersion = '4.0.2.RELEASE'
springPluginVersion = '0.8.0.RELEASE'
springShellVersion = '1.1.0.BUILD-SNAPSHOT'
springSocialTwitterVersion = '1.1.0.RELEASE'
springVersion = '4.0.3.RELEASE'
tomcatJdbcPoolVersion = '7.0.42'
tomcatVersion = '7.0.35'
uuidVersion = '3.2'
validationApiVersion = '1.0.0.GA'
zookeeperVersion = '3.4.6'

// Hadoop Versions
hadoop22Version = '2.2.0'
cdh5Version = '2.3.0-cdh5.0.0'
hdp21Version = '2.4.0'
phd1Version = '2.0.5-alpha-gphd-2.1.0.0'
phd20Version = '2.2.0-gphd-3.0.1.0'

singleNodeServerProcess = new SingleNodeServerProcess()
}
```

after

```
ext {
	// Not in IO
	args4jVersion = '2.0.16'
	curatorVersion = '2.5.0'
	equalsverifierVersion = '1.1.3'
	ftpServerVersion = '1.0.6'
	greenmailVersion = '1.3.1b'
	hamcrestDateVersion = '0.9.3'
	jcloudsVersion = '1.7.0'
	postgresqlVersion = '9.2-1002-jdbc4'
	splunkVersion = '1.2.0'
	springBatchAdminMgrVersion = '1.3.0.M1'
	springIntegrationSplunkVersion = '1.1.0.M2'
	springShellVersion = '1.1.0.BUILD-SNAPSHOT'
	uuidVersion = '3.2'
	zookeeperVersion = '3.4.6'

    // Also in IO
    nettyVersion = '3.6.6.Final' // N.B. Reactor depends on Netty 4
	springBatchVersion = '3.0.1.BUILD-SNAPSHOT'

	// Hadoop Versions
    springDataHadoopBase = '2.0.0.RELEASE'
	hadoop22Version = '2.2.0'
	cdh5Version = '2.3.0-cdh5.0.0'
	hdp21Version = '2.4.0'
	phd1Version = '2.0.5-alpha-gphd-2.1.0.0'
	phd20Version = '2.2.0-gphd-3.0.1.0'

	singleNodeServerProcess = new SingleNodeServerProcess()
}
```