Add example for each libssh2 example

[volks73]

The libssh2 C library has many examples for implementing various features with communication via a SSH connection. LabVIEW-based examples should be created for each of these examples using this toolkit.

[volks73]

While not a full-fledged example at the moment, a VI snippet for executing a single command on a remote SSH server was added to the Examples section of the README in ded132e.

Some additional details were also added about the origins and similarities of each VI snippet in the README to examples from the libssh2 C library.

[volks73]

Added a single command execution example based on the VI snippet as of eee9329.

[volks73]

Added an example for executing multiple commands with a single channel as of fc15a75. This is not strictly an example from the libssh2 library, but it is a question that appears to come up frequently on their mailing list and a product of #5.

[volks73]

Added an example for executing multiple, sequential commands using multiple channels as of 7334dd7. This is not strictly an example from the libssh2 library, but it is useful based on discussions from #5.

[volks73]

Added examples for uploading and downloading small files using SFTP as of 3f8c4df. This is not strictly an example from the libssh2 library but these are very close to the sftp.c and sftp_write.c examples.

[keinstein]

Maybe I have overlooked it, but as far as I can see, none of the examples qualifies for the first 'S' in Secure SHell, as the server can be any man-in-the-middle without authenticating the server to the client. Could someone add an example of server key verification based on contemporary cryptographic hashes (both md5 and sha1 should be considered to be unsafe)?

Both scenarios are interesting: Key verification and known_hosts-file based verification.