Update Jsch to version 0.1.49 from 0.1.48.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs/trunk@1447676 13f79535-47bb-0310-9956-ffa450edef68
Use org.bouncycastel:bcprov-jdk16 instead of org.bouncycastle:bcprof-jdk15on since Java 1.6 is required.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs/trunk@1447683 13f79535-47bb-0310-9956-ffa450edef68