Changes in v2.15

Fixed an issue that was preventing code from being instrumented (and coverage markers showing) under VS2015 RC.

Removed the .NET 4.5.3 task runner, as 4.5.3 no longer exists.

Added a task runner for .NET 4.5.2.

Added a task runner for .NET 4.6.  This is now also used for hosting NCrunch under VS2015.

Added client-side support for the upcoming NCrunch License Server.

Adjusted the NCrunch build engine so it will now rewrite/fix 'dangerous' relative SDK assembly reference 
hintpaths that would likely fail to correctly resolve inside NCrunch workspaces.

Fixed an issue where Debug.Write(null) statements could cause tests to fail with an exception.

Adjusted the new NCrunch version notification box so that it will warn the user if their license is more than 
a year old and is due for upgrade.