Fix compiler plugin variable names; drop compiler config as now redundant

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project/trunk@1494154 13f79535-47bb-0310-9956-ffa450edef68
Bug in Apache pom means we cannot drop the compiler config.

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project/trunk@1494165 13f79535-47bb-0310-9956-ffa450edef68
Oops, copied from previous revision and forgot to revise the name ...

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project/trunk@1494166 13f79535-47bb-0310-9956-ffa450edef68
Upgraded maven javadoc to 2.9.1

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project/trunk@1497681 13f79535-47bb-0310-9956-ffa450edef68