Modify nunitlite to display multiple assert information

[CharliePoole]

Currently, we use the single failure message created for compatibility in order to display the result of a test using multiple asserts. It should use the actual result of each assert to display both the message and stack frame. The code will be similar to the console runner so it may be best to wait for that to be done.

[CharliePoole]

This should be part of the nunit/nunit#391 Epic but it looks like we might have to first merge the boards for the two repositories.