Made MessageObject an object
To green
Merge branch 'feature/message-object' of git://github.com/Yavari/log4net.ElasticSearch into Yavari-feature/message-object

Conflicts:
	src/log4net.ElasticSearch.Tests/ElasticSearchAppenderTests.cs
	src/log4net.ElasticSearch.Tests/LogEvent.cs
Merge branch 'master' into Yavari-feature/message-object

Conflicts:
	src/log4net.ElasticSearch/ElasticSearchAppender.cs
	src/log4net.ElasticSearch/Models/LogEvent.cs
#21 Change exception and messageObject properties to object so that are not squashed by a ToSTring and can fully populate dynamically in ES