Previously, if users of our code put the API folder in their pyshared
they would have to import it as "humbug.humbug". By moving Humbug's API
into a directory named "humbug" and moving the API into __init__, you
can just "import humbug".
(imported from commit 1d2654ae57f8ecbbfe76559de267ec4889708ee8)
The old-style api.humbug is deprecated, so we rewrite the path for things
to work correctly.
(imported from commit 360282b70fab1ad9d9d517157fc4fe06f9acd6a2)