* Use native go method to get current user rather than environment var

* Use t.Skip instead of return in test

Executed go fmt

getEngine() not handles DB parameters (#2972) (#2974)

Uses .AllCols() for Update in updateMirror()

Spanish traslation removed

Fixed a wrong way to ommit the --prune option in process.ExecDir() for MirrorUpdate function

The same logic was duplicated in three places. Factor it
out so that we can add further fallbacks in a single place.

This adds a sqlite build tag so that you don't have to have the sqlite
import commented out in code and users can run:
    go build -tags sqlite
if they want to have sqlite support enabled.  It is disabled by default
so nothing changes with the default go get or build commands.