Michal Čihař - Weekly phpMyAdmin contributions 2017-W43

Weekly phpMyAdmin contributions 2017-W43

Last week was mostly focused on code cleanup. I've done quite some fixups in the database interface layer, which now has easier to use API and no more relies on global variables to store database links. Pretty much similar was done in the authentication layer, where many of the methods had names coming from historical reasons rather than their current functionality.

Handled issues: