get hostname only once
use DateFormatUtils from commons-lang that is thread safe
organize imports and format code (intellij style)
millisec precision is back (with test)
fix small typo compatability/compatibility
Merge pull request #11 from looztra/optimize2

Optimize : request hostname to system only once and use DateFormatUtils for date formating
Update Contributors.md
ignoring timestamp test for now
[maven-release-plugin] prepare release jsonevent-layout-1.3
[maven-release-plugin] prepare for next development iteration
Merge branch 'master' into fasterxml

Conflicts:
	src/main/java/net/logstash/log4j/JSONEventLayout.java
	src/test/java/net/logstash/log4j/JSONEventLayoutTest.java