Switch from MySQL 5.5 to MariaDB 5.5

[ottok]

This is the first step in #876 and #949. Switching to MariaDB available
in the official Ubuntu 14.04 repositories is a very safe change and
it paves way to easily upgrade to 10.0 or 10.1 in a later step.

[ottok]

Please switch from MySQL to MariaDB

Motivation:

• Many are upgrading from Oracle MySQL to truly open source MariaDB by original creators of MySQL. Oracle only publishes code dumps at release time, and is not viewed as a true open source project, while MariaDB is developed fully in the open.
• Most of the Linux ecosystem has already switched to MariaDB. For example Fedora/RedHat and SUSE ship by default only MariaDB since a few years back. MariaDB has been available in Ubuntu since 14.04 and in Debian since version 8. Debian is going to have MariaDB as default in next release and Ubuntu is likely to follow.
• Projects like XAMPP already has MariaDB as default.
• Automattic, the company behind WordPress, is a sponsor of the MariaDB Foundation and all new WordPress.com deployments use MariaDB.
• Also many other prominent sites have switched to MariaDB, like Wikipedia.org and Google. More details at https://en.wikipedia.org/wiki/MariaDB
• Techincal benefits listed at https://seravo.fi/2015/10-reasons-to-migrate-to-mariadb-if-still-using-mysql

This change is the first one in a series of changes to implement MariaDB in VVV. I am committed to take care of the following steps too.

I have tested that the current patch works as expected in all relevant scenarios:

• New installs (vagrant up on a pristine machine)
• Existing installs that update VVV (vagrant up will work, DB stays provided by mysql-server package)
• Existing installs that download a new image but has older VVV version (vagrant up will work, DB stays provided by mariadb-server)

[cfoellmann]

I am looking forward to it.
You identified the blockers we face and I will give feedback if possible.

Go for it!!

[ottok]

I am happy to continue working on this if you can give me some assurance that my work is not in vain and this first step is merged.

Next steps could be improving the default config to be WordPress-friendlier, e.g. have UTF8MB4 as the default character set so that emoticons 🍔 are correctly saved in the database etc. Lot's of people want to use emoticons in WordPress comments! :)

MariaDB in Debian and Ubuntu is by default wiht UTF8MB4 so this would all be nicely aligned with future production environments.

[ottok]

Ping @jeremyfelt - I am happy to rebase and refine, I just want to have some thumbs up that the PR will be processed and my work is not in vain..

Greetings from WordCamp Stockholm Contributor Day! :)

[ottok]

I rebased on latest develop and extended with UTF-8 support. Please review and merge @jeremyfelt @LoreleiAurora

Thanks!

[LoreleiAurora]

I am happy for this to be merged, waiting for feedback from others.

[jeremyfelt]

This looks great! @ottok - should this still be merged as the first step toward the upgrade to MariaDB 10?

[ottok]

Yes please :)

[jeremyfelt]

I'm going to merge this in so that we're part way there. Let's move to 10 next. :)

[ottok]

Thanks! I'll work on a 10.0 (or perhaps even a 10.1) upgrade soon.