Both Result and Choice for error handling

[wallymathieu]

• Forked individual files from #31 and reverted original files
• Added Compatibility namespaces and moved some Choice constructs into these
• Renamed Notification.Error to Notification.Exception in order to avoid confusing things with Result<,>

[wallymathieu]

Note that I've added same kind of test as can be found for Fold for FoldBack @jack-pappas

[wallymathieu]

@vasily-kirichenko and @jack-pappas thoughts? Does it look ok?

[jack-pappas]

Thanks @wallymathieu — I’ll take a look at this over the weekend.

[vasily-kirichenko]

@jack-pappas could you please publish a new NuGet package after merging this PR?

[wallymathieu]

https://gist.github.com/wallymathieu/ad8fe3d5b85875cf6f487ad0180be660 ?

[wallymathieu]

Should we perhaps try to split this pull request into more granular parts? A lot changes are mostly copy and modify (in order to be compatible). @vasily-kirichenko do you have an idea of how this could be done?

[vasily-kirichenko]

Is there a plan to merge this?

[wallymathieu]

Should we close this pull request @jack-pappas (as it is to big) ?

[wallymathieu]

I'm closing this PR as it is probably to big to review or accept. Best of luck!

[vasily-kirichenko]

@jack-pappas Please, merge this PR. I had to build an ExtCore package myself and publish it on a private server, everything's been working OK.

[wallymathieu]

Since @vasily-kirichenko says that it's working fine, I've reopened the pull request

[vasily-kirichenko]

Yes, it's working 100% fine.

[wallymathieu]

Then perhaps move this PR to point to another branch on this repository in order to iterate on it?

[vasily-kirichenko]

@wallymathieu Could you merge master into it to make AppVeyor happy?

[wallymathieu]

Will do!