[MGPG-41] Passphrase revealed when backspacing at prompt

o Fixed for Java 1.6+ using reflection. Bug will still be present on JVM 1.5

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1570549 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare release maven-gpg-plugin-1.5

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1570552 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1570554 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare release maven-gpg-plugin-1.5

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1570556 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1570558 13f79535-47bb-0310-9956-ffa450edef68