Glances 3.2.0

This release is a major version (but minor number because the API did not change). It focus on
CPU consumption. I use Flame profiling https://github.com/nicolargo/glances/wiki/Glances-FlameGraph_
and code optimization to reduce CPU consumption from 20% to 50% depending on your system.

Enhancement and development requests:

* Improve CPU consumption
    - Make the refresh rate configurable per plugin #1870
    - Add caching for processing username and cmdline
    - Correct and improve refresh time method
    - Set refresh rate for global CPU percent
    - Set the dafault refresh rate of system stats to 60 seconds
    - Default refresh time for sensors is refresh rate * 2
    - Improve history perf
    - Change main curses loop
    - Improve Docker client connection
    - Update Flame profiling
* Get system sensors temperatures thresholds #1864
* Filter data exported from Docker plugin
* Make the Docker API connection timeout configurable
* Add --issue to Github issue template
* Add release-note in the Makefile
* Add some comments in cpu_percent
* Add some comments to the processlist.py
* Set minimal version for PSUtil to 5.3.0
* Add comment to default glances.conf file
* Improve code quality #820
* Update WebUI for security vuln

Bugs corrected:

* Quit from help should return to main screen, not exit #1874
* AttributeError: 'NoneType' object has no attribute 'current' #1875
* Merge pull request #1873 from metayan/fix-history-add
* Correct filter
* Correct Flake8 issue in plugins
* Pressing Q to get rid of irq not working #1792
* Spelling correction in docs #1886
* Starting an alias with a number causes a crash #1885
* Network interfaces not applying in web UI #1884
* Docker containers information missing with Docker 20.10.x #1878
* Get system sensors temperatures thresholds #1864

Contibutors for this version:

* Nicolargo
* Markus Pöschl
* Clifford W. Hansen
* Blake
* Yan