completed work on b:tabView and b:tab and added a Maven pom.xml

- This pull request (actually the previous one) adds a Maven pom.xml. Note serveral features are missing, such as extracting CSS and JS code from Bootstrap, minification and Proguard.

- The request also contains some polishing on b:tabView and b:tab.

Usage:
```XML
<b:tabView activeIndex="2">
	<b:tab title="Project explorer">This is the first tab.</b:tab>
	<b:tab title="Navigator">This is the second tab.</b:tab>
	<b:tab title="Type Hierarchy">
		<h:graphicImage library="images" name="type.png"></h:graphicImage>
	</b:tab>
	<b:tab title="Package explorer">
		<h:graphicImage library="images" name="package.png"></h:graphicImage>
	</b:tab>
</b:tabView>
```
yields
![image](https://cloud.githubusercontent.com/assets/3045767/4968176/bfe8984e-6836-11e4-90a7-571f6ca7e5e7.png)