* CIs: attempt to use csources_v1
* also updated the BSDs
* also updated azure pipelines
* std modules should not itself use the 'std/' import dir...
* compiler has to be careful with std/ for v1 booting
(cherry picked from commit a9b62de895)
* Error -> Defect for defects
The distinction between Error and Defect is subjective,
context-dependent and somewhat arbitrary, so when looking at an
exception, it's hard to guess what it is - this happens often when
looking at a `raises` list _without_ opening the corresponding
definition and digging through layers of inheritance.
With the help of a little consistency in naming, it's at least possible
to start disentangling the two error types and the standard lib can set
a good example here.