* mariadb: update "What is MariaDB?"
Update description/license plege based on https://mariadb.org/about/
Update predominate users based on more recentl wikipedia links.
Drop-in compatibility is considered by many as overstepping the mark,
despite being moderately true, so limit the statement somewhat.
* mariadb: change hosting repository
* mariadb: replace logo
From https://mariadb.org/wp-content/uploads/2019/01/mariadb_org_rgb_v.png
* mariadb: reference JIRA for issues
* mariadb: content reference mariadb command line and docs
* mariadb: reference as MariaDB logs/configuration file
* mariadb: change README-short.txt
* mariadb: update maintainer
* mariadb: add get-help.md
* mariadb: *.sql.xz files initialization allowed
* mariadb: network naming from #1860
This should make it much faster to find the right place to file issues, get help, find out whether upstream maintains an image, etc.
I've done my best to represent each `REPO/maintainer.md` file appropriately, but I might have missed some (or there might be something else a maintainer prefers be listed there, either more or less descriptive, for example), which would be welcome contributions following this change.
Daniel Black
