Fixing crash on editing notes node

- EditWindow is a popup window, hence it's visual tree doesn't contain
DynamoView class. Thus the Owner is set as null and later OnClick()
crashes while calling ExecuteCommand on owner.
- Fixed by locating the DynamoView object from
Application.Current.MainWindow.
Only use regex based search as fallback when not enough search results are returned
Do proper speed comparison
Cleanup stopwatch and old search code
A few fixes
Merged UpdateGraphAsyncTask/EngineController for immediate review
Fixing crash while launching Package Manager website from Manage Package Manager UI.
Fixes crash while copy paste of custom node.

- Nickname is not serialized while copying custom node and while pasting
it was trying to get it and hence crashed.
- Fixes http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-4235
IgnoreCase in MatchWithQueryString
Store all tags in lower case in SearchDictionary
Only construct special query string once
Only do fallback search when special characters are present
Cleanup of ignored language test cases
more cleanup
Fix nunit tests caused by null session
Merge pull request #2221 from Randy-Ma/unit_tests

Fix nunit tests caused by null session
Merge pull request #2198 from pboyer/SearchSpeed

Improve node library search speed
Fix #2199, aka MAGN-4271
Merge pull request #2205 from sharadkjaiswal/MAGN-4235

Fixes crash while copy paste of custom node.
Synced LibG DLLs to latest