Redirects Logger.Log(a, b, ex) to Logger.LogException(a, b, ex)

[alexangas]

Fixes issue #91, for method signatures Log<TArgument>(LogLevel, string, TArgument) where TArgument is of base type Exception, along with related helper methods.

Another candidate for this is Log(LogLevel, string, object) where object is an Exception, and there may also be others. Please let me know if you would like these added.

As this is a behaviour change (although I think this would be viewed as expected) - perhaps a mention should be made in the next release notes? Or even a config option?

[ghost]

Thanks for the pull request, I'll look into to it next week when I back
from vacation

[ilya-g]

What if I write Log.Info("The exception is: {0}", ex) by intent? Suppose that I want exception to be rendered in LogEvent's message as string, and not stored in Exception property.

I suggest to check message contains format placeholder {0} and redirect to LogException only if this placeholder is missing.

Also, please note that since methods such as Log(Level, message, TArgument) are marked with [StringFormatMethod("message")] attribute, ReSharper will complain, if you specify argument and not specify format placeholder in the message.