[SSHD-380] Refactor tests to let the system choose the port instead of using getFreePort() which can lead to problems
[SSHD-382] Add support for custom properties on the command line for client and server
[SSHD-383] Support for loading ecdsa keys in the client demo
[SSHD-384] Fix broken client demo when executing a command
[SSHD-385] Fix log statement when a window is unblocked
[SSHD-386] Allow controlling socket options