Update javadoc, cannot find CustomDBNameResolver
add Sebastian Groebler to list of CLAs
add tavis config file
Ensure that logback-classic builds with Travis
add CLA for A. Dorokhine
AppenderBase started variable made volatile as it is mutable, access to it is not synchronized and it is shared between threads.
Fix for http://jira.qos.ch/browse/LOGBACK-1037
Merge pull request #229 from Mahoney/fix-non-threadsafe-appender

AppenderBase started variable made volatile
suppres --> suppress
Merge pull request #231 from rtack/patch-1

Fixed typo in configuration.html
Update CONTRIBUTING.md
Update CONTRIBUTING.md
Merge pull request #220 from wuwen5/fix-warning-CustomDBNameResolver

Update javadoc, cannot find CustomDBNameResolver