Make usage documentation consistent and also demoose

[mattias-p]

Purpose

This PR kills two birds with one stone:

• It fixes the discrepancy between perldoc zonemaster-cli and zonemaster-cli --help, and
• it migrates away from Moose and Moosex::Getopt::GLD.

Context

• Fixes Inconsistent CLI options documentation #68.
• I've tried to keep this PR conservative with regards to improving the actual help text. I have a lot of improvements in mind but I'm deferring them to one or more followup PRs. See Organize --help text #389.

Changes

Application:

• Instead of using Moose and Moosex::Getopt::GLD we now Getopt::Long and Pod::Usage which are both Perl core modules.
• I merged the best parts of the --help and perldoc usage texts. As I worked through them I realized there was a lot of room for further improvement. I tried to be conservative making improvements but in some cases I couldn't help myself.

Tests:

• A unit test is added to make sure --help work.
• A unit test is added to make sure all POD is syntactically correct.

Documentation:

• The --help text is longer now and formatted differently. This because we're using a different method of generating it and the details are taken from POD instead of Moose attributes.

Reviewing this PR

• Inspect the help text and man page of both this branch and the develop branch looking details that have gone missing.

Testing this PR

• Unit tests should pass.
• Perform a limited amount of exploratory testing for edge cases like missing required arguments, unknown options, invalid arguments, or conflicting flags.

[matsduf]

I guess .travis.yml should also be updated to match the update. The installation instruction also needs an update.

[mattias-p]

I've split out #381 from this PR and rebased this one on top of that one.

[matsduf]

The man page starts with

zonemaster-cli --test=delegation/delegation01 --level=debug zonemaster.net

The easier and preferred format is

zonemaster-cli --test=delegation01 --level=debug zonemaster.net

[matsduf]

zonemaster-cli -h gives brief information now, and that is fine, but I do not get any information on how to get full information. zonemaster-cli --help gives brief information. Is it possible to give it paged like a man page? perldoc Zonemaster::CLI gives no information. Maybe refer to man zonemaster-cli and zonemaster-cli --help?

[matsduf]

I think zonemaster-cli with no argument should refer to some documentation like "--help".

[matsduf]

zonemaster-cli --help gives less information than man zonemaster-cli. Preferably it should be the same, or the former refer to the latter. The man page comes from the script. Couldn't --help extract the POD from the script and show that paged? I know that is possible to achieve.

[mattias-p]

The man page starts with

zonemaster-cli --test=delegation/delegation01 --level=debug zonemaster.net

The easier and preferred format is

zonemaster-cli --test=delegation01 --level=debug zonemaster.net

As I state in the PR description I'm deferring all improvements to the text. If you look at #389 you'll see that I update the SYNOPSIS section so that it declares the command line syntax instead of just a selection of examples.

[matsduf]

@mattias-p, please look at issue #388. I think you are behind that code.

[mattias-p]

@matsduf As you discovered I had forgotten to implement the --help aliases. I've force-pushed implementation and automatic test for that. Please review again.

[marc-vanderwal]

Looks good to me.