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.
New travis config
Merge github.com:Getty/p5-moox-cmd