* extract runtime building from cfg
* respect AURRPCURL
* use -Syu if there are no targets, allows to pass extra options
* one more step towards removing runtime from cfg
* add missing locales
* use t.Setenv instead of os.Setenv for tests
* locale: present y/n if localisation is not latin. Always accept y/n in every case
* question: use operation info for question
* edge case where localised n is equal to default y
* add tests for basic locales