Make --help and --version information a bit more uniform.

Have --version print the version number, the copyright information, the
"compiled with" information, the "running on/with" information, and the
compiler information.

Have --help print the version number, a one-line summary of what the
program does, a reference to http://www.wireshark.org for more
information, a Usage: line, and a list of command-line options.

This means programs doing that don't need to include version.h; that's
left up to get_ws_vcs_version_info() to do.

Change-Id: Idac641bc10e4dfd04c9914d379b3a3e0cc5ca8cb
Reviewed-on: https://code.wireshark.org/review/2794
Reviewed-by: Guy Harris <guy@alum.mit.edu>