MCHANGES-341 Externalize JIRA server timeout values to the configuration section.

As suggested by Dennis Lundberg, prefix parameters with jira to make it more clear
that this will only effect issue retreivals from JIRA.

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1626681 13f79535-47bb-0310-9956-ffa450edef68