zerolog.Context now knows how to LoggerRef()

[rsrchboy]

This should be simple enough -- same as Logger(), but with a different return, useful for chaining with WithContext().

I've included a simple test case, just to demonstrate this addresses the issue in #116

Fixes #116

[rs]

This is confusing and is bloating the lib API.

[rsrchboy]

So, in #116 you invited a fix / PR to address the issue; this is the approach that was discussed.

Do you have an alternate approach to suggest, or should #116 be closed as wontfix?

[rs]

The discussed solution was to make WithContext a non pointer method. See #116 (comment)

[rsrchboy]

Ah. I was going off of the prior comment #116 (comment), and looking for a minimal "won't break anything" solution.