Adding support for Embeddable Build Status Icon

## This pull request adds support for passthrough of the embeddable build status icon(s)

(see #5 for more information / history)

### To enable the embeddable build status icon passthrough
To enable the embeddable build status icon passthrough, perform the following steps:

### 1. manually upload the plugin and restart Jenkins

Package the plugin:

```
mvn package
```

and upload it:

![upload](https://dl.dropbox.com/s/srukykaaqump9a5/Jenkins%20-%20Upload%20Plugin.png?token_hash=AAHTVZzA5tVLWcZKBKx-iYcUY_K4VwEQSw4ie9n0lfEphg&dl=1)

### 2. configure Jenkins' global security
![configure](https://dl.dropbox.com/s/g0pqf1jrthw5wll/Jenkins%20-%20Configure%20Global%20Security.png?token_hash=AAG94N3LRZ5DBaI_pRLIhNKWgvRpKYVyKoRpLUlXSS0h7w&dl=1)

### 3. enable READ access to the build status icon
![enable read](https://dl.dropbox.com/s/sf731hr9f4glsm8/Jenkins%20-%20enable%20build%20status%20icon.png?token_hash=AAFO326GiOQkqvvHdL-xv23N0Wv_QlxGasZCZ0tyJe6Yrw&dl=1)

### 4. open one of the jobs' [embeddable build status](https://wiki.jenkins-ci.org/display/JENKINS/Embeddable+Build+Status+Plugin)
![job](https://wiki.jenkins-ci.org/download/attachments/60918124/snapshot1.png?version=2&modificationDate=1336589268000)

### 5. and use the embeddable build status icon [externally](https://github.com/PhenotypeFoundation/GSCF#war-files)
![icon](https://wiki.jenkins-ci.org/download/attachments/60918124/ebs.png?version=1&modificationDate=1336586636000)