Add backtrace information to log and stdout. Update console help behavior.

Changes:

* add backtrace information to log and stdout;
* add hint where user can find additional information;
* add version call;
* add information about required -c option to banner.

Example:

      [root@fuelweb ~]# astute -f /opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/astute-0.0.1/astute2.yaml -c provision
      {"status"=>"error", "error"=>"Cobbler error", "progress"=>100}
      Error: #<StopIteration: StopIteration>
      Hint: use astute with --verbose or check log (/var/log/astute.log) for more details

Log:

      2013-07-30T13:10:48 err: [9841] Error occured while provisioning: #<Timeout::Error: execution expired>
      2013-07-30T13:10:48 err: [9841] /opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/astute-0.0.1/lib/astute/orchestrator.rb:68:in `rescue in fast_provision'
      /opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/astute-0.0.1/lib/astute/orchestrator.rb:71:in `fast_provision'
      /opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/astute-0.0.1/bin/astute:85:in `console_provision'
      /opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/astute-0.0.1/bin/astute:101:in `<top (required)>'
      -e:1:in `load'
      -e:1:in `<main>'