Bug fixes, new features, subclassing support for tagview, NSAttributed String support, and more!

[Luke-k-dev]

Hi!

I added the support for the following:

• Subclassing TagView. This allows subclassed tags to override their appearance from the tag view. This way you can have tons of differently styled tag in 1 taglistview bug free.
• NSAttributedString. This allows for text attachment and more customization with tag views. (THis also supports strings for highlight and selected states that are attributed too!)
• Bug fixes for layout. (When using 2 cells with different font sizes the rows would not layout correctly. This is now fixed.)

I also updated the example project to show how to use the new features. (The hetroTagListView shows how using many different cells works. The custom classes are at the bottom of the view controller.)

Please let me know if there are any problems!

• Luke

[abdulla-allaith]

Any plans to merge this?
This would resolve #217 and #41, allowing AttributedString usage.

[abdulla-allaith]

This would be a great PR to merge.
I am currently using a fork with this PR merged in PROD.
Working flawlessly.