`get_term()` now returns a `WP_Term` object, instead of a `stdClass` object.
Cache support and sanitization filters for individual terms are now more
centralized. For example, `get_term_by()` is able to cast results of its query
to a `WP_Term` object by passing it through `get_term()`.
The `$taxonomy` parameter for `get_term()` is now optional, as terms ought to
be unique to a taxonomy (ie, shared terms no longer exist). In cases where
`get_term()` detects that the term matching the specified term_id is from the
wrong taxonomy, it checks to see if you've requested a shared term, and if so,
it splits the term. This is used only for fallback purposes.
The elimination of shared terms allows the caching strategy for terms to be
simplified. Individual terms are now cached in a single 'terms' bucket.
Props flixos90, boonebgorges, scribu, dipesh.kakadiya.
See #14162.
git-svn-id: https://develop.svn.wordpress.org/trunk@34997 602fd350-edb4-49c9-b593-d223f7449a82
