Introduce and use a new `get_core_post_statuses()` method to get an array of default post status objects
Introduce an internal object cache for repeat requests to `get_custom_statuses()`
Leverage the internal object cache when using `get_custom_status_by()`
Rename our cache variable for verbosity
Introduce an internal object cache for `get_editorial_metadata_terms()`
`get_custom_status_by()` should support "name" out of principle too
Leverage our internal object cache for getting an editorial metadata term
Use our helper function instead of `get_term_by()` because the former is nicely cached
Update readme
Change the behavior of `generate_post_li_html()` such that we can fragment cache and decrease the display time of each item
Update readme again
Merge pull request #235 from Automattic/cache-get-term-by-235

Cache use of get_term_by()