add version command to witness node and to cli_wallet

[oxarbitrage]

A witness user of peerplays(block producer or api node) or a cli_wallet user cant know what version of the software they are running.

A --version command can be added to the binaries so they can have this information available.

this is done in bitshares with the following pull requests:

• add version command to node bitshares/bitshares-core#524
• move version command code bitshares/bitshares-core#536

[bobinson]

witness_node works now

root@xyz ~/src/peerplays #witness_node --version
Version: 1.3.1
Git Revision: 62ddd67
Built: Sep 7 2019 at 20:26:04
SSL: OpenSSL 1.0.2g 1 Mar 2016
Boost: 1.67

cli_wallet fails:
**root@xyz ~/src/peerplays # ** cli_wallet --version
terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injectorboost::program_options::unknown_option >'
what(): unrecognised option '--version'
Aborted