[FIXED JENKINS-18591] - Sporadic connection failures

Jsch bug http://sourceforge.net/p/jsch/bugs/58/ causes random connection
failures. Fixed in Jsch 1.50 - updating dependency
Merge pull request #1 from svogt/JENKINS-18591

[FIXED JENKINS-18591] - Sporadic connection failures
Don't follow IOExceptions
[FIXED JENKINS-17965 JENKINS-17383] parse timezone in server response
[maven-release-plugin] prepare release cvsclient-71-jenkins-10
[maven-release-plugin] prepare for next development iteration
Only back-up files if we've forced a clean and the file seems to have changed
Allow entries to be retrieved for file being cleaned
[maven-release-plugin] prepare release cvsclient-71-jenkins-11
[maven-release-plugin] prepare for next development iteration