bump reqd version of MooX::Cmd and MooX::Options

MooX::Options 3.99 in conjunction with MooX::Cmd 0.007 supports sub-commands
and --man for more detailed help.
improve documentation for auto-man

Since MooX::Option 3.99 in addition to --help the option --man exists
whoch displays a larger help. For special options which might need more
explanation, long_doc for automatically generated manpage is added.
apply Perl::Tidy
use Alien::Packages to guess pkgsrc-prefix

Relax pkgsrc parameters:
* return usage when pkgsrc base dir not found
* try to find pkgsrc prefix when not specified using Alien::Packages