Expose full list of extensions for a mimetype

[loudwinston]

CHANGE SUMMARY

Update to provide new extensions method to expose full list of valid extensions for a mimetype. Existing extension method semantics are unchanged, so this should be fully backward compatible.

Documentation and tests are updated to reflect these changes.

[loudwinston]

Can this be reviewed / merged? My team relies on these changes and we don't want to maintain our own branch in perpetuity.

[loudwinston]

@broofa Can you please comment, merge, or close this PR? It's been open for 4 months now without any comments.

[dougwilson]

So a similar API is being proposed to the mime-types module, but under the method name .allExtensions rather than .extensions. I'm sure there are a lot of folks subscribed to this repo, so are there any thoughts on the different names? Personally, I think .extensions() as in this PR seems the best, since it goes well with the .extension() API and keeps with the pattern of all current methods being lower-cased.

Thoughts?

[broofa]

Sounds like mime-types module has this covered