ARC support, Setup with Interface, NSArray to populate Bar Chart (or XML), Easier Customization, Better Demo, Documentation

We've put a lot of time and effort into this pull request, which makes major improvements to the Bar Chart Project. We plan to continue to make improvements. Major steps have been taken to better document this project too. Here's what we've done so far:

<table>
  <tr><th colspan="2" style="text-align:center;"><b>Version 3.0</b></th></tr>
  <tr>
    <td>Setup a Bar Chart using only Storyboards / XIBs. Load data into a Bar Chart using an NSArray. Customize the visual appearance of a Bar Chart.
    <ul>
   		<li>Bar Charts can be added directly from the interface instead of through code. Just add a <tt>UIView</tt> to your View Controller and change its class to <tt>BarChartView</tt>. Then set it up in your implementation. Take a look at the improved sample project for more information.</li>
   		<li>Load data into a Bar Chart using an <tt>NSArray</tt> rather than an XML File. Use the new method to format and generate data for use with a Bar Chart: <tt>[createChartDataWithTitles: values: colors: labelColors:]</tt>. Refer to the new documentation for more information.</li>
   		<li>Less formatting is required for XML data loading. Use <tt>[dataWithContentsOfFile: values: colors: labelColors:]</tt> to set Bar Chart properties (rather than doing so in your XML file). Refer to the new documentation for more information.</li>
   		<li>Set which axis to display using the <tt>AxisDisplaySettings</tt> type. You can set this property when loading data into your Bar Chart</li>
   		<li>Added new methods and types to change the visual appearance of the Bar Chart</li>
   		<li>Fixed bugs and memory leaks</li>
   		<li>Code cleanup and reorganization to make it easier on the eyes.</li>
	<ul>
  </td>
  </tr>
  <tr><th colspan="2" style="text-align:center;"><b>Version 2.0</b></th></tr>
  <tr>
    <td>This update makes large improvements to the performance of code by converting the project to Objective-C ARC.  </br> 
    <ul>
   <li>Converted project to ARC. If your project does not use ARC, add the ARC flag to the <b>Bar Chart</b> files in your project's Compile Sources section: <tt>-fobjc-arc</tt>.</li>
    <li>Improved the demo app. The demo app now runs on iPhone 5 and iOS 5 or higher. It also begins the transition to a more interface based Bar Chart integration system.</li>
    <li>Code cleanup and reorganization to make it easier on the eyes.</li>
    <li>Project now compiles with ARMV7 and ARMV7S instead of ARMV6</li>
    <ul>
    </td>
  </tr>
</table>

Here's a preview of the improved interface and demo app: 
![screenshot](https://f.cloud.github.com/assets/2374407/615937/2482b84e-ce4f-11e2-95ca-ecc5b65da735.png)

We hope you like the pull request and merge it! If there are any issues or you have any feedback - we'd love to hear it. Thanks for making a great library that we (and hopefully many others) can use and continue to improve upon!