Matplotlib's ConciseDateFormatter-like formatter in pandas.plotting._matplotlib.converter.py
Matplotlib has a nice formatter class named matplotlib.dates.ConciseDateFormatter, which is a candidate to become Matplotlib's default date formatter in future versions (as of MPL 3.1.1, see 
[Matplotlib documentation](https://matplotlib.org/gallery/ticks_and_spines/date_concise_formatter.html)).

It would be nice if the converters defined in pandas.plotting._matplotlib.converter.py
could provide the same date formatting, especially regarding the pandas data types like Period.