bump Module::Pluggable version to stop 5.18 from

whining and let it work smoothly on blead
allow commands show available neighbours/children
some safety first checks and minor optimizations
remove trailing \t
simplify loading commands to avoid stack frames
move initialization sequence for cmd into role

as discussed with primary author, a role having all neat information about
the cmd state in attributes is smarter that passing arguments ...
allow Class->new_with_cmd->execute(...)
improve documentation
move initialization to MooX::Cmd::Role

* as discussed with Getty in #web-simple, let MooX::Cmd be a bootstrap
  loader only and modern implementations can do
  with "MooX::Cmd::Role";
* allow modify all initialization parameters via class _build_ functions
  (called in class context, but as method)
add some samples to role

author wants ('examples') x INT_MAX - unfortunately he gets only one
add some comfort as primary author desires

To avoid scaring users the Getty wants some improved examples and an
accessor for last cmd in chain.