Refactor Breadcrumb class

- Removes legacy support for making the last crumb a link
- Removes unused `reset()` and `last()` methods
- Adds `CSS` classes and `nav` element
- Ensures each title is always wrapped in an `itemprop` span
- Modernizes, clarifies, and optimizes functionality
- Adds unit test
- Updates template

Note:  This class violates the [Single Responsibility Principle (SRP)](http://en.wikipedia.org/wiki/Single_responsibility_principle) in that it both collects breadcrumb links and renders them.  These two concerns should be kept separate.
<a href='#crh-start'></a><a href='#crh-data-%7B%22processed%22%3A%20%5B%22https%3A//github.com/zencart/zc-v1-series/pull/147%23issuecomment-55201716%22%2C%20%22https%3A//github.com/zencart/zc-v1-series/pull/147%23issuecomment-55292586%22%2C%20%22https%3A//github.com/zencart/zc-v1-series/pull/147%23issuecomment-55292729%22%2C%20%22https%3A//github.com/zencart/zc-v1-series/pull/147%23issuecomment-55299893%22%5D%2C%20%22comments%22%3A%20%7B%22General%20Comment%22%3A%20%7B%22html_url%22%3A%20%22https%3A//github.com/zencart/zc-v1-series/pull/147%23issuecomment-55201716%22%2C%20%22comments%22%3A%20%5B%7B%22body%22%3A%20%22%40zcwilt%20there%27s%20not%20much%20to%20annotate%20on%20those%20docblocks%2C%20so%20I%20was%20just%20being%20%27efficient%27.%20%20Still%2C%20it%27s%20just%20an%20irrelevant%20style%20issue%20that%27s%20not%20worth%20quibbling%20over.%20%20I%27ve%20updated%20them%20for%20consistency.%22%2C%20%22created_at%22%3A%20%222014-09-10T23%3A53%3A52Z%22%2C%20%22user%22%3A%20%7B%22avatar_url%22%3A%20%22https%3A//avatars.githubusercontent.com/u/1590605%3Fv%3D2%22%2C%20%22html_url%22%3A%20%22https%3A//github.com/texdc%22%7D%7D%2C%20%7B%22body%22%3A%20%22%3A%2B1%3A%20%22%2C%20%22created_at%22%3A%20%222014-09-11T16%3A45%3A34Z%22%2C%20%22user%22%3A%20%7B%22avatar_url%22%3A%20%22https%3A//avatars.githubusercontent.com/u/227354%3Fv%3D2%22%2C%20%22html_url%22%3A%20%22https%3A//github.com/zcwilt%22%7D%7D%2C%20%7B%22body%22%3A%20%22%3Ashipit%3A%22%2C%20%22created_at%22%3A%20%222014-09-11T16%3A46%3A26Z%22%2C%20%22user%22%3A%20%7B%22avatar_url%22%3A%20%22https%3A//avatars.githubusercontent.com/u/227354%3Fv%3D2%22%2C%20%22html_url%22%3A%20%22https%3A//github.com/zcwilt%22%7D%7D%2C%20%7B%22body%22%3A%20%22Let%27s%20just%20hope%20that%20the%20features%20you%27ve%20removed%20aren%27t%20things%20the%20end-users%20have%20been%20using%20or%20wish%20to%20have.%20After%20all%2C%20that%27s%20the%20reason%20why%20they%20were%20left%20in%20the%20code%20despite%20the%20default%20template%20not%20implementing%20them.%5Cr%5Cn%5Cr%5CnFor%20now%2C%20%3A%2B1%3A%20%22%2C%20%22created_at%22%3A%20%222014-09-11T17%3A38%3A02Z%22%2C%20%22user%22%3A%20%7B%22avatar_url%22%3A%20%22https%3A//avatars.githubusercontent.com/u/404472%3Fv%3D2%22%2C%20%22html_url%22%3A%20%22https%3A//github.com/drbyte%22%7D%7D%5D%2C%20%22title%22%3A%20%22General%20Comment%22%7D%7D%2C%20%22approved%22%3A%20%7B%22https%3A//github.com/zcwilt%22%3A%20%7B%22avatar_url%22%3A%20%22https%3A//avatars.githubusercontent.com/u/227354%3Fv%3D2%22%7D%7D%7D'></a>
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<img src='http://www.codereviewhub.com/site/github-approved-avatar.png'><a href='https://github.com/zcwilt'><img src='https://avatars.githubusercontent.com/u/227354?v=2' width=34 height=34></a>

- [x] <a href='#crh-comment-General Comment'></a> <img src='http://www.codereviewhub.com/site/github-completed.png' height=16 width=60>&nbsp;<b><a href='https://github.com/zencart/zc-v1-series/pull/147#issuecomment-55201716'>General Comment</a></b>
- <a href='https://github.com/texdc'><img border=0 src='https://avatars.githubusercontent.com/u/1590605?v=2' height=16 width=16'></a> @zcwilt there's not much to annotate on those docblocks, so I was just being 'efficient'.  Still, it's just an irrelevant style issue that's not worth quibbling over.  I've updated them for consistency.
- <a href='https://github.com/zcwilt'><img border=0 src='https://avatars.githubusercontent.com/u/227354?v=2' height=16 width=16'></a> :+1:
- <a href='https://github.com/zcwilt'><img border=0 src='https://avatars.githubusercontent.com/u/227354?v=2' height=16 width=16'></a> :shipit:
- <a href='https://github.com/drbyte'><img border=0 src='https://avatars.githubusercontent.com/u/404472?v=2' height=16 width=16'></a> Let's just hope that the features you've removed aren't things the end-users have been using or wish to have. After all, that's the reason why they were left in the code despite the default template not implementing them.
For now, :+1:


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