test bed for email sending client

As I promised, v1.35 now has full documentation on howdy_email_demo_gui, the prototype reStructuredText email sending client. There are some small improvements I can make

1. lower level upstream Imgur front end need not be limited to PNG files. Can also include JPEG, GIF, TIF, SVG image files.

2. Allow for attachments, limited to 15 MB total.

improvements on email gui functionalities

Created a test-bed for sending out generic email using restructuredtext. Made a very simple sending-email client where you can specify TO/CC/BCC emails, FROM address, and PNG images inline into email. Uses Imgur for inlining images into email, and the GMail API to send emails.

v1.35 will arise ONCE I change the placeholder documentation, howdy_create_texts, to correct documentation for howdy_email_demo_gui.

Removal of all mention of Plexstuff, many minor improvements

final cleanup of Plexstuff, and bunches of minor improvements to documentation and code.

Plexstuff is now Howdy!

Plexstuff is now Howdy! No significant change in functionality beyond fixing papercuts, but this repo and this SDK is now called Howdy

19 AUGUST 2020 release

Consists of many commits between release 1.11 (from 9 NOVEMBER 2019) to today (19 AUGUST 2020). Therefore, I feel this warrants a new release, even though changes in functionality are relatively minor.

Checkpoint, finished CLIs, plex configuration, PyQt5 migration

1. Finished documentation, and implementation, of modifying main Imgur album.

2. Finished migration of current GUIs and module level GUI code to PyQt5.

preliminary documentation of all CLIs, lower-level APIs.

1. FINALLY FINISHED 1st iteration of documenting all the non-GUI, lower level APIs, and all CLI tools.

2. Remaining functionality for the foreseeable future will consist of documenting the GUIs and constructing comprehensive and USEFUL tests.