Rightalign numeric values

[muhqu]

addresses #85

The Pretty Printing was done via gherkin.formatter.PrettyFormatter which is part of cucumber/gherkin. This pull request copied the original PrettyFormatter and added the missing feature to right-align numeric values in tables.

[muhqu]

I just noticed that upgrading the gherkin lib to 2.12.2 was not needed, as I ended up copying the PrettyFormatter anyway...

[muhqu]

I rebased the PR to remove the unnecessary gherkin lib upgrade.

[ilanpillemer]

I am a bit uncomfortable with duplicating the code from Gherkin. We should just just use the Gherkin library, @aslakhellesoy - any thoughts?

[muhqu]

I wanted to subclass the pretty formatter to add the missing features but its implementation relies heavily on private fields and methods which make it hard to add these.

It would make sense to apply the changes I made to the pretty formatter also to the gherkin lib. It is just that I don't like to have to wait for them to review,merge and release these missing features until I can use them were I need them... ;-) if they accept my pull requests, I'll be happy to switch back to the original gherkin lib.

The pretty formatter is very much self contained. E.g. a single class file.

[muhqu]

@ilanpillemer FYI: I just submitted a PR for the gherkin lib to add some formatting options I want to add to cucumber-eclipse... cucumber/gherkin#331

[muhqu]

💡 it might be nice to allow users to configure a command-line formatter... I've written such a tool in golang: it's name is gherkinfmt and it uses my go-gherkin package...

[muhqu]

Added another PR #107 which supersedes this one... still leaving this one open, as it could still be merged independently...