default mime type for files without extensions should be "text/plain"

[jankeromnes]

Our current type system assumes that files without extensions are binary.

While that is a common assumption is OSes, I believe it is wrong and unnerving (especially in tree) for the following reasons:

• tree is inherently more about text files than about binary files, it is safer to assume text
• files without extensions are most commonly: created from gateway.html, scripts, or both (and why the hell would we require users to call everything "*.txt")
• actual binary files on tree are most commonly identified with extensions: mp3, ogg, jpg, png, pdf, zip...
• actual binary files without extensions are more of an edge case: they will need to be handled as such (e.g. if we build binaries like firefox or chromium, we'll make sure to mark them explicitly as binary)

@espadrine please let's change our type logic to default to the text/plain mime type when no extension was found.

[jankeromnes]

Following discussion on IRC, it seems that adding a "type": { "": "text/plain" } entry in /'s metadata fixes the problem. No need to make the whole type system default to "text/plain".

@espadrine said he'll add this in his next pull request, which is exciting :)

[espadrine]

Note: pull request #195 fixes the undermining issue.

[jankeromnes]

Fixed!