When doing repeated testing, the mirrorsort can add unwanted delay.
This commit adds support for setting EQUO_MIRRORSORT=0 to disable this
and use the default sort order while testing.
It preserves the previous behaviour and defaults to 1.
Call to equo query puts arg '--quiet' in the wrong place, receiving
prettified output which doesn't match string comparisons against
package names, leading to all dependencies being reinstalled every
time. This commit puts the --quiet arg in to correct place so that
only missing dependencies are installed.