Arrow: Add support for reversed humanize

[paulschmeida]

I think it would be nice if there was a reversed version of humanize, i.e. a function that parses human readable input like "20 hours ago" and produces an Arrow object than can be used in scripts with ease.

[ju2pom]

Exactly what I need !

[andrewelkins]

361 would address this I think

[systemcatch]

Despite the linked PR now being closed, this is still something we'd like to implement. I think we could do with a good idea for structure + spec before we PR this again though.

[abschmidt6]

I'm interested in working on this feature, I will take a look at it!

[jadchaar]

Fantastic. Let us know if you have any questions.

[sawhitt]

I am interested in working on this, would that be alright?

[jadchaar]

Sure go for it @sawhitt !

[systemcatch]

772 was a good try at implementing this functionality but it failed to account for any locales other than English. Future attempts at this should take into account that many languages don't separate with spaces (Chinese, Japanese) and don't always have a value followed by a unit (Swedish).

[anishnya]

I am interested working on this issue.

[systemcatch]

Now that #956 has been merged I think we can close this.