Add Esperanto support to NumberToWords. Fixes #558

[aloisdg]

Here is a checklist you should tick through before submitting a pull request:

• Implementation is clean
• Code adheres to the existing coding standards; e.g. no curlies for one-line blocks, no redundant empty lines between methods or code blocks, spaces rather than tabs, etc.
• No ReSharper warnings (Is there a global R# file?)
• There is proper unit test coverage
• If the code is copied from StackOverflow (or a blog or OSS) full disclosure is included. That includes required license files and/or file headers explaining where the code came from with proper attribution
• There are very few or no comments (because comments shouldn't be needed if you write clean code)
• Xml documentation is added/updated for the addition/change (needed?)
• Your PR is (re)based on top of the latest commits from the dev branch (more info below)
• Link to the issue(s) you're fixing from your PR description. Use fixes #<the issue number>
• Readme is updated if you change an existing feature or add a new one (Is there a list of language supported?)
• Run either build.cmd or build.ps1 and ensure there are no test failures (failed but work in VS)

[aloisdg]

How can I see the log of AppVeyor? I get — AppVeyor was unable to build non-mergeable pull request but I find it not very helpful.

[hangy]

No idea on how to get the log (might only be visible to an admin), but I just ran the build.cmd on your branch and it built just fine. Maybe just a transient error?

[aloisdg]

@hangy Thank you for your feedback

[hazzik]

@onovotny can you take a look?

[clairernovotny]

@hazzik @aloisdg I had to revert as I saw build errors: Build fails with eo-EO is an invalid culture identifier