Web.py

* Make `reloader` work when `code.py` is called with a full path. (tx David Terrell)

* Fixed bug in `strips()`. (tx Michael Josephson)

* Fixed: application.load() assumes ctx.path will be a latin1 string 687
* Fixed: can not reset session data to same value as initialized. 683
* Fixed: can not set session expire time. 655
* Fixed: not export session store `MemoryStore`.

* setup.py: Add python_requires='>=3.5' 662

* Python-2 support has been completely dropped. Welcome to Python 3.
* Fixed: session store `DiskStore` doesn't return correctly if session
directory doesn't exist. 652
* Fixed: incorrect str/bytes type of session data. 644 645
* Fixed: `db.query("insert... returning")` fails to commit. 648 649

* New session store `MemoryStore`, used to save a session in memory.
Should be useful where there are limited fs writes to the disk, like
flash memories. 174
* Fixed: not support `samesite=none`. 592
* Fixed Python-3 compatibility issues: 574, 576.
* Support tuple and set in `sqlquote()`.
* Drop support for SQL driver `pgdb`. It was dead, you cannot even find its
website or download link.
* Drop support for SQL driver `psycopg`. The latest version was released in
2006 (14 years ago), please use `psycopg2` instead.
* Removed function `web.safemarkdown`. if it's used in your application, you
can install the `Markdown` module from pypi
(https://pypi.org/project/Markdown/), then replace `web.safemarkdown()` by
`markdown.markdown()`.