Added release and RC tag management tasks

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project-release-tools/trunk@1520895 13f79535-47bb-0310-9956-ffa450edef68
Improved release and RC tag management tasks

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project-release-tools/trunk@1521411 13f79535-47bb-0310-9956-ffa450edef68
Fixed imports

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project-release-tools/trunk@1521414 13f79535-47bb-0310-9956-ffa450edef68
Revert local snapshot prior to choosing a new release version

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project-release-tools/trunk@1521435 13f79535-47bb-0310-9956-ffa450edef68
Integrated RC dist generation tasks into build.gradle

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project-release-tools/trunk@1521762 13f79535-47bb-0310-9956-ffa450edef68
Cleaned up release management and release candidate tasks

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project-release-tools/trunk@1522479 13f79535-47bb-0310-9956-ffa450edef68
Added site generation tasks

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/project-release-tools/trunk@1523595 13f79535-47bb-0310-9956-ffa450edef68