DynamoDS/Dynamo — pull request #1495 by Benglin (2014-04-13 11:14:45+00:00)
Title: Retiring Info Bubble from various part of Dynamo

##### Background
Info Bubble, or how it was implemented in the past, was more complex than it really needed to be. The MVVM separation of its components were done incorrectly with calls going through layers that were not necessary. This resulted in poor performance and undesirable patches made to workaround issues that it has with cross thread updates.

##### Changes
This pull request replaces most of the Info Bubble codes with WPF tool-tips for the following reasons:
- The Info Bubble does not offer anything more than a WPF tool-tip can offer
- WPF tool-tips are lightweight
- WPF tool-tips are fully XAML based, therefore allowing greater customization
- WPF tool-tip works seamlessly across list items (i.e. node ports) without delay seen in Info Bubble
- Mouse handling codes are completely removed as tool-tip natively handles them

##### Note to code reviewer
Both ```Convert``` and ```ConvertBack``` methods are required by ```IValueConverter``` interface. One-way data binding usually does not require implementation of ```ConvertBack``` method since it will never be called (like a ```NodeState``` affects the color of a node, but the color of the node will not be changed by a user. And even if it does change, there is no way a change in node color should update ```NodeState```). In view of this, ```ConvertBack``` methods usually just throw ```NotImplementedException``` and do nothing more. Having to add a message in such exceptions might be a little overkill, IMHO. But if a change is still desirable, then please let me know I will attempt to add some messages.