initial support for enstratius location

this is the first commit to support enstratius on brooklyn

- this location uses [cloudsoft/enstratus-client](https://github.com/cloudsoft/enstratius-client) library 0.0.1-SNAPSHOT deployed at [Sonatype](https://oss.sonatype.org/content/repositories/snapshots/io/cloudsoft/enstratius/enstratius-client/0.0.1-SNAPSHOT/)

- it requires Guava 14+ because it uses *com.google.common.io.BaseEncoding.base64*
- this PR attaches new location to brooklyn's pom.xml
```xml
        <profile>
            <id>Locations</id>
            <activation> <property><name> !brooklyn.explicitModules </name></property> </activation>
            <modules>
                <module>locations/jclouds</module>
                <module>locations/enstratius</module>
            </modules>
        </profile>
```