Add properties from the logger context as fields
Handle null context
Fix tabs/spaces
Clear Eclipse warning
Merge branch 'master' of github.com:logstash/logstash-logback-encoder
Merge branch 'add-context-properties' of https://github.com/tmeighen/logstash-logback-encoder into tmeighen-add-context-properties

Conflicts:
	src/main/java/net/logstash/logback/encoder/LogstashEncoder.java
	src/test/java/net/logstash/logback/encoder/LogstashEncoderTest.java
Merge branch 'refs/heads/tmeighen-add-context-properties'
Tidy-up
Updating contributors
Update logback
Update Jackson